#include #define REP(i, n) for(int i = 0;i < n;i++) #define ll long long using namespace std; //typedef vectorvec; //typedef vectorvec; //typedef vector mat; typedef pair P; typedef pair LP; const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1}; const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1}; const int INF = 1000000000; const ll LINF = 1000000000000000000;//1e18 const ll MOD = 1000000007; const double PI = acos(-1.0); const double EPS = 1e-10; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } template inline void add(T &a, T b){a = ((a+b) % MOD + MOD) % MOD;}; int main(){ cin.tie(0); ios::sync_with_stdio(false); string S, T; cin >> S >> T; int N = S.size(), M = T.size(); if(M == 1){ if(S.find(T) != string::npos){ cout << -1 << endl; return 0; } } int ans = 0; for(int i=0;i