printed p1 aaaa 1
printed p1 bbbb 2
printed p1 cccc 3
printed p1 dddd 4
printed p1 eeee 5
printed p1 ffff 6
printed p3 1111 1
printed p4 &&&& 1
printed p3 2222 2
printed p4 $$$$ 2
sent p4 **** p2 3
received p2 **** p4 4
printed p3 3333 3 
printed p4 ^^^^ 4
printed p1 gggg 7
printed p2 xxxx 5
printed p2 yyyy 6