#include <iostream>
#include <vector>
using namespace std;

int main() {
    vector<vector<int>> vec(3, vector<int>(2, 1));
    vec[1].push_back(3);
    vec.push_back(vector<int>{4, 5});
    cout << vec.size() << "," << vec[1].size() << "," << vec[3][1];
    return 0;
}