/a[11 171{0}repeat]def/b 172 array def(1.6)print 1 1 166{/i exch def 0 1000{2
copy add 2 idiv a i 2 index put i 1 i 3 add{b exch 0 0 1 3 index{a 3 index 2
index sub get exch a exch get mul add}for put}for 0 i 3 add -1 1{b exch get add
1000 idiv}for 4 lt{2 copy sub 1 eq{exit}if exch}{exch pop}ifelse}loop 1000 add
4 string cvs 1 3 getinterval print}for