#include <iostream>
using namespace std;
int n, m;
int a[105][105], sum[105][105];
int main()
{
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			cin >> a[i][j];
			sum[i][j] = sum[i - 1][j] + sum[i][j - 1] - sum[i - 1][j - 1] + a[i][j];
		}
	}
	//计算左上顶点(x1,y1)到右下顶点(x2,y2)矩形的面积
	int ans = sum[x2][y2] - sum[x1 - 1][y2] - sum[x2][y1 - 1] + sum[x1 - 1][y1 - 1];
			
		
	
}