# (ax+b)/(cx+d) = 0, NO, INF
a, b, c, d = 1, 1, 2, 2  # ответ NO
#a, b, c, d = 2, -4, 7, 1 # ответ 2

# ax+b=0 => ax=-b => x=-b/a
# cx+d≠0 => cx≠-d => x≠-d/c

if a == 0:
    if b == 0:
        print("INF")
    else:
        print("NO")
else:
    x = -b//a
    if c==0 or x == (-d//c):
        print("NO")
    else:
        print(x)