class Solution {
public:
    int repeatedStringMatch(string a, string b) {
        int len_a = (int) a.size(), len_b = (int) b.size();
        string tmp = "";
        int rep = len_b / len_a;
        for(int i = 0; i < rep; i++) {
            tmp += a;

        }
        for(int i = 0; i < 5; i++) {

            if(tmp.find(b) != string::npos) {
                return rep;
            }
            tmp += a;
            rep++;
        }
        return -1;
    }
};