first iteration:
./marian/build/marian --model mt.npz \
--type transformer --overwrite \
--train-sets mt-summit-corpora/mt-summit-corpora/dev/dev.en \
mt-summit-corpora/mt-summit-corpora/dev/dev.pl \
--disp-freq 1000 \
--save-freq 1000 \
--optimizer adam \
--lr-report

next iterations:
./marian/build/marian --model mt.npz \
--type transformer --overwrite \
--train-sets mt-summit-corpora/mt-summit-corpora/dev/dev.en \
mt-summit-corpora/mt-summit-corpora/dev/dev.pl \
--disp-freq 1000 \
--save-freq 1000 \
--optimizer adam \
--lr-report \
--pretrained-model mt.npz

./marian/build/marian --model mt.npz \
--type transformer --overwrite \
--train-sets mt-summit-corpora/mt-summit-corpora/train/train.en \
mt-summit-corpora/mt-summit-corpora/train/train.pl \
--disp-freq 1000 \
--save-freq 10000 \
--optimizer adam \
--lr-report \
--pretrained-model mt.npz