U.

#include <bits/stdc++.h>
using namespace std;

int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<int>> c(n + 1, vector<int>(m + 1));
    vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= m; ++j){
            cin >> dp[i][j];
        }
    }
    dp[0][1] = 1;
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= m; ++j){
            if(dp[i][j] == 1){
                dp[i][j] = dp[i-1][j] + dp[i][j-1];
            }
        }
    }
    if(!dp[n][m]){
        cout << "Impossible\n";
        return 0;
    }
    cout << dp[n][m] << endl;
}