Don't Try to Count

    #include<bits/stdc++.h>
    using namespace std;

    int flag;

    int is_substring(string x, string s){
        if(x.find(s)==string::npos){
            if(s.size()*x.size()>=630){
                flag=0;
                cout<<"-1\n";
                return 0;
            }
            return 1;
        }
        return 0;
    }

    int main(){
        int t;
        cin >> t;

        while(t--){
            int n, m;
            flag=1;
            string x, s, x_temp;

            cin >> n >> m;
            cin >> x >> s;
            int count=0;

            while(is_substring(x, s)){
                x_temp=x;

                x.append(x_temp);

                count++;
            }

            if(flag)
                cout << count << "\n";
        }
    }