Input/output two-dimensional array

#include <iostream>
#define MAXN 10
using namespace std;

void input_2d(int &n, int &m, int a[][MAXN]) {
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> a[i][j];
        }
    }
}

void output_2d(int &n, int &m, int a[][MAXN]) {

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cout << a[i][j] << " ";
        }
        cout << endl;
    }
}

int main() {

    int a[MAXN][MAXN], n, m;
    input_2d(n, m, a);
    output_2d(n, m, a);
    return 0;
}