a, b = input().split()
while eval(a) or eval(b):
if a > b:
a, b = b, a
a = a[:: -1]
b = b[:: -1]
c = 0
d = 0
for e in range(len(a)):
if eval(a[e]) + eval(b[e]) + c >= 10:
c = 1
d += 1
else:
c = 0
for e in range(len(a), len(b)):
if eval(b[e]) + c >= 10:
c = 1
d += 1
else:
c = 0
if d > 1:
print(d, 'carry operations.')
elif d:
print(d, 'carry operation.')
else:
print('No carry operation.')
a, b = input().split()
自己python測試和這裡的測試都對，但送出之後就是RE，說string index out of range