b = 1
print (n++ " " b);

sum a = a = 2
set b = Set(b += (sum a = (a = 2)))
print (n++ " " b);

for (v=3, oo, if (!set search(set b, v), set b = set union(set b, Set (b += (sum a += (a = v)))); print (n++ " " b); if (n==10 000, break)))

quit