#include <iostream>
#include <climits>
using namespace std;

int m, n, s = 0, target;
int a[10][10];         
bool v[10][10]; 
int ans = INT_MAX;
int dx[] = {0, 0, 1, -1}; 
int dy[] = {1, -1, 0, 0};

void dfs(int x, int y, int sum, int count) {
    if (sum > target || count >= ans) return;  // 剪枝
    if (sum == target) {
        ans = min(ans, count);
        return;
    }
    
    for (int i = 0; i < 4; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        if (nx >= 0 && nx < n && ny >= 0 && ny < m && !v[nx][ny]) {
            v[nx][ny] = true;
            dfs(nx, ny, sum + a[nx][ny], count + 1);
            v[nx][ny] = false;  // 回溯
        }
    }
}

int main() {
    cin >> m >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> a[i][j];
            v[i][j] = false; 
            s += a[i][j];
        }
    }
    if (s% 2 != 0) {  // 总和为奇数，无法分割
        cout << 0 << endl;
        return 0;
    }
    
    target = s / 2;
    v[0][0] = true;
    dfs(0, 0, a[0][0], 1);
    
    if (ans == INT_MAX) {
        cout << 0 << endl;  // 无法分割
    } else {
        cout << ans << endl;
    }
    
    return 0;
}