Can someone tell me what's wrong with my code please?

include

include

include

using namespace std;

int main() { string str1; int N, q, k_size;

getline(cin, str1);
N = str1[0] - '0';
q = str1[2]-'0';
vector<vector<int>> a(N);
getline(cin, str1);

cout << N << " " << q << endl;
for (int i = 0; i < N; i++) {
    getline(cin, str1);
    k_size = str1[0] - '0';
    vector<int> k(k_size);

    for (int j = 0; j < k_size; j++)
        k[j] = str1[j + 2];

}
for (int i = 0; i < 2; i++) {
    getline(cin, str1);
    cout << a[str1[0] - '0'][str1[2] - '0'] << endl;
}




return 0;

}