#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1505, mod = 1000000007;
int qkpow(int a, int b) {
	int ans = 1; for (; b; b >>= 1, a = 1ll * a * a % mod) if (b & 1) ans = 1ll * ans * a % mod; return ans;
}
int fact[MAXN * 100], invf[MAXN * 100];
void mul(int *F, int *G, int *H, int k) {
	for (int i = 0; i <= k; i++) {
		__int128 X = 0; for (int j = 0; j <= i; j++) X += 1ll * F[j] * G[i - j]; H[i] = X % ::mod;
	}
}
int f[41][MAXN], f2[38][MAXN], ftmp[MAXN], g[1505];
int read() {
	char ch; while ((ch = getchar()) <= ' '); int x = ch - '0';
	while ((ch = getchar()) > ' ') x = 10 * x + ch - '0'; return x;
}
int main() {
	int n = read(), m = read();
	fact[0] = 1; for (int i = 1; i <= n * m; i++) fact[i] = 1ll * fact[i - 1] * i % mod;
	invf[n * m] = qkpow(fact[n * m], mod - 2);
	for (int i = n * m - 1; ~i; i--) invf[i] = 1ll * invf[i + 1] * (i + 1) % mod;
	for (int i = 1; i <= n; i++) ftmp[i] = invf[i * m - 1];
	f[0][0] = 1;
	for (int i = 1; i <= 40; i++) mul(f[i - 1], ftmp, f[i], n);
	f2[0][0] = 1; for (int i = 1; i <= 37; i++) mul(f2[i - 1], f[40], f2[i], n);
	for (int i = 1; i <= n; i++) {
		int i1 = i % 40, i2 = i / 40; __int128 X = 0;
		for (int j = 0; j <= n; j++) X += 1ll * f[i1][j] * f2[i2][n - j];
		ftmp[i] = X % mod * fact[n * m - i] % mod;
	}
	g[0] = 1; for (int i = 0; i < n * m; i++) {
		int a = read(); for (int j = n; j; j--) g[j] = (g[j] + 1ll * g[j - 1] * a) % mod;
	}
	int A = 0; for (int i = 1; i <= n; i++) A = (A + 1ll * ftmp[i] * g[i]) % mod; printf("%d", A);
}