ababcabcacbab
abcac

6

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))