// Program to check matrix is scalar matrix or not.
#include <bits/stdc++.h>
#define N 4
using namespace std;

// Function to check matrix is scalar matrix or not.
bool isScalarMatrix(int mat[N][N])
{
	// Check all elements except main diagonal are
	// zero or not.
	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++)
			if ((i != j) && (mat[i][j] != 0))
				return false;

	// Check all diagonal elements are same or not.
	for (int i = 0; i < N - 1; i++)
		if (mat[i][i] != mat[i + 1][i + 1])
			return false;
	return true;
}

// Driver function
int main()
{
	int mat[N][N] = { { 2, 0, 0, 0 },
					{ 0, 2, 0, 0 },
					{ 0, 0, 2, 0 },
					{ 0, 0, 0, 2 } };
	// Function call
	if (isScalarMatrix(mat))
		cout << "Yes" << endl;
	else
		cout << "No" << endl;
	return 0;
}