#include #define REP(i,x) for(int i=0,i##_len=(x);i struct RollingHash { vector< unsigned > hashed, power; inline unsigned mul(unsigned a, unsigned b) const { unsigned long long x = (unsigned long long) a * b; unsigned xh = (unsigned) (x >> 32), xl = (unsigned) x, d, m; asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod)); return m; } RollingHash(const string &s, unsigned base = 10007) { int sz = (int) s.size(); hashed.assign(sz + 1, 0); power.assign(sz + 1, 0); power[0] = 1; for(int i = 0; i < sz; i++) { power[i + 1] = mul(power[i], base); hashed[i + 1] = mul(hashed[i], base) + s[i]; if(hashed[i + 1] >= mod) hashed[i + 1] -= mod; } } unsigned get(int l, int r) const { unsigned ret = hashed[r] + mod - mul(hashed[l], power[r - l]); if(ret >= mod) ret -= mod; return ret; } unsigned connect(unsigned h1, int h2, int h2len) const { unsigned ret = mul(h1, power[h2len]) + h2; if(ret >= mod) ret -= mod; return ret; } int LCP(const RollingHash< mod > &b, int l1, int r1, int l2, int r2) { int len = min(r1 - l1, r2 - l2); int low = -1, high = len + 1; while(high - low > 1) { int mid = (low + high) / 2; if(get(l1, l1 + mid) == b.get(l2, l2 + mid)) low = mid; else high = mid; } return (low); } }; using RH = RollingHash< 1000000007 >; int main(){ string s,t; cin>>s>>t; assert(s.size()<=1000); assert(t.size()<=1000); if(t.size()==1&&s.find(t.front())!=string::npos){ cout<<-1<