#include<bits/stdc++.h>
using namespace std;
int main(){
int n = 3;
int m = 4;
// Create a vector containing n
//vectors of size m.
vector<vector<int> > vec( n , vector<int> (m, 0));
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++){
cout<< vec[i][j]<< " ";
}
cout<< "\n";
}
return 0;
}