Moscow QF 2017 G

#include <iostream>

using namespace std;

const int SIZE = 500 + 10;

using lint = long long;

int N, M;
lint row[SIZE], col[SIZE];
int r[SIZE][SIZE], c[SIZE][SIZE];



int main() {
    scanf("%d%d",&N,&M);
    for(int i = 0; i < N; ++i) {
        for (int j = 0; j < M; ++j) {
            scanf("%d%d",&r[i][j], &c[i][j]);
            row[i] += c[i][j];
            col[j] += r[i][j];
        }
    }
    for (int i = 0; i < N; ++i) {
        if (row[i]) {
            printf("No\n");
            return 0;
        }
    }
    for (int i = 0; i < M; ++i) {
        if (col[i]) {
            printf("No\n");
            return 0;
        }
    }
    printf("Yes\n");
    return 0;
}