✅ 정답 공개
def kmp(text, pattern):
n,m=len(text),len(pattern)
fail=[0]*m
j=0
for i in range(1,m):
while j>0 and pattern[i]!=pattern[j]: j=fail[j-1]
if pattern[i]==pattern[j]: j+=1; fail[i]=j
j=0
for i in range(n):
while j>0 and text[i]!=pattern[j]: j=fail[j-1]
if text[i]==pattern[j]: j+=1
if j==m: return i-m+1
return -1
text=input()
pattern=input().strip()
print(kmp(text, pattern))