String Substr and Find

1#include <iostream>
2#include <string>
3using namespace std;
4 
5int main() {
6    string s = "programming";
7    cout << s.substr(0, 7) << endl;
8    cout << s.substr(7) << endl;
9    cout << s.find("gram") << endl;
10    cout << s.length() << endl;
11    return 0;
12}