diff --git a/cw4zadDom/client b/cw4zadDom/client
new file mode 100755
index 0000000..df1d0b1
Binary files /dev/null and b/cw4zadDom/client differ
diff --git a/cw4zadDom/client.c b/cw4zadDom/client.c
new file mode 100644
index 0000000..7097b53
--- /dev/null
+++ b/cw4zadDom/client.c
@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+int main(int argc, char **argv)
+{
+    if (argc < 2) {
+        printf("podaj numer portu jako parametr\n");
+        return 1;
+    }
+    
+    struct sockaddr_in endpoint;
+    int sdsocket, addrlen, i, received;
+    struct hostent *he;
+    char *port = argv[1];
+    // char host[100] = "150.254.79.244";
+    char host[100] = "127.0.1.1";
+    long message = 426083, receivedMessage;
+
+    he = gethostbyname(host);
+
+    endpoint.sin_family = AF_INET;
+    endpoint.sin_port = htons(atoi(port));
+    endpoint.sin_addr = *(struct in_addr*) he->h_addr;
+    addrlen = sizeof(struct sockaddr_in);
+
+    if ((sdsocket = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
+        printf("socket() %d nie powiodl sie\n", i);
+        return 1;
+    }
+
+    if (connect(sdsocket,(struct sockaddr*) &endpoint, addrlen) < 0) {
+        printf("connect() %d nie powiodl sie\n", i);
+        return 0;
+    }
+
+    message = htonl(message);
+    send(sdsocket, &message, sizeof(message), 0);
+
+    
+    received = 0;
+
+    while (received < sizeof(long))
+    {
+        received += recv(sdsocket, 
+                            &receivedMessage, 
+                            sizeof(long), 
+                            0);
+    }
+
+    receivedMessage = ntohl(receivedMessage);
+
+    receivedMessage += 1;
+    receivedMessage = htonl(receivedMessage);
+    send(sdsocket, &receivedMessage, sizeof(long), 0);
+
+    
+    return 0;
+}
diff --git a/cw4zadDom/server b/cw4zadDom/server
new file mode 100755
index 0000000..b7be55f
Binary files /dev/null and b/cw4zadDom/server differ
diff --git a/cw4zadDom/server.c b/cw4zadDom/server.c
new file mode 100644
index 0000000..55de69b
--- /dev/null
+++ b/cw4zadDom/server.c
@@ -0,0 +1,108 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+struct sockaddr_in endpoint;
+FILE *flog;
+char myhostname[1024];
+
+int main(int argc, char **argv) {
+    long lnIn1, lnIn2, lhIn1, lhIn2, lhOut, lnOut;
+    int sdServerSocket, sdConnection, retval;
+    socklen_t sin_size;
+    struct sockaddr_in incoming;
+    struct hostent *heLocalHost;
+    char sign;
+
+    sin_size = sizeof(struct sockaddr_in);
+
+    sdServerSocket = socket(PF_INET, SOCK_STREAM, 0);
+    gethostname(myhostname, 1023);
+    heLocalHost = gethostbyname(myhostname);
+
+    endpoint.sin_family = AF_INET;
+    endpoint.sin_port = htons(14444);
+    endpoint.sin_addr = *(struct in_addr*) 
+                        heLocalHost->h_addr;
+    memset(&(endpoint.sin_zero),0,8);
+
+    printf("slucham na(listening on) %s:%d\n",
+           inet_ntoa(endpoint.sin_addr),
+           ntohs(endpoint.sin_port));
+
+    retval = bind(sdServerSocket,
+                  (struct sockaddr*) &endpoint,
+                  sizeof(struct sockaddr));
+
+    if (retval < 0) {
+        printf("bind nie powiodl sie (bind failed)\n");
+        return 1;
+    }
+
+    listen(sdServerSocket, 10);
+
+    sin_size = sizeof(struct sockaddr_in);
+    while ((sdConnection =
+
+            accept(sdServerSocket,
+                   (struct sockaddr*) &incoming,
+                   &sin_size))
+
+            > 0) {
+        printf("Polaczenie z (connection with)%s:%d\n",
+               inet_ntoa(incoming.sin_addr),
+               ntohs(incoming.sin_port));
+
+        if (recv(sdConnection, &lnIn1, sizeof(long),0) 
+            != sizeof(long)) {
+            printf("pierwszy recv nie powiodl sie (first recv failed)\n");
+            close(sdConnection);
+            continue;
+        }
+        lhIn1 = ntohl(lnIn1);
+
+        lhOut = random();
+        lnOut = htonl(lhOut);
+
+        if (send(sdConnection, &lnOut, sizeof(long), 0) 
+            != sizeof(long)) {
+            printf("send nie powiodl sie (send failed)\n");
+            close(sdConnection);
+            continue;
+        }
+
+        if (recv(sdConnection, &lnIn2, sizeof(long), 0) 
+            != sizeof(long)) {
+            printf("drugi recv nie powiodl sie (second recv failed)\n");
+            close(sdConnection);
+            continue;
+        }
+
+        lhIn2 = ntohl(lnIn2);
+
+        flog = fopen("zad.txt","a");
+        if (lhIn2 == lhOut + 1) sign = '+'; 
+        else sign = '-';
+        fprintf(flog,"%c %ld from %s:%d : %ld, %ld\n",
+                sign,
+                lhIn1,
+                inet_ntoa(incoming.sin_addr),
+                ntohs(incoming.sin_port),
+                lhOut,
+                lhIn2);
+
+        close(sdConnection);
+        fflush(flog);
+        fclose(flog);
+    }
+
+    printf("Blad sieci (network error)\n");
+    fclose(flog);
+    return 0;
+}