avg of elements in a matrix

#include <iostream>
using namespace std;

int main() {
    int row,col;
    cin>>row>>col;
    
    int matrix[row][col];
    
    for(int i=0;i<row;i++){
        for(int j=0;j<col;j++){
            cin>>matrix[i][j];
        }
    }
    
    float sum=0.0;
    for(int i=0;i<row;i++){
        for(int j=0;j<col;j++){
            sum += matrix[i][j];
        }
    }
    
    float avg = sum/(row*col);
    cout<<avg;
    return 0;
}