#include <bits/stdc++.h>

using namespace std;
const int INF = 0x3f3f3f3f;

int main() {
    string x = "ABCDEFG";
    cout << x.substr(0, 2) << endl; //从索引0开始，截取2个长度
    cout << x.substr(2) << endl;    //从索引2开始，截取到结尾
    /*
    输出:
    AB
    CDEFG
    */
    return 0;
}