while True:
a,b,x,y = map(int,input().split())
if a+b+x+y == 0:
break
for i in range(1,101):
a0 = a * i / 100
b0 = b * i / 100
if not ((a0 <= x and b0 <= y) or (a0 <= y and b0 <= x)):
print("{}%".format(i-1))
break
else:
print("100%")