H.cpp

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<array<int,2>> vii;
typedef vector<int> vi;
#define INF 1000000000
#define MOD 1000000007
 
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }
 
    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};
 
int dp[1002][1002]; 
bool tr[1002][1002];
 
void solve() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <=n; ++i) {
        for (int j = 1; j <= m; ++ j) {
            char c;
            cin >> c;
            if (c == '#') tr[i][j] = 1;
        }
    }
    if (!tr[1][1])
        dp[1][1] = 1;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            if (i == 1 && j == 1) continue;
            if (!tr[i][j]) {
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
                dp[i][j] %= MOD;
            }
        }
    }
    cout << dp[n][m] << "\n";
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    int t = 1;
    //cin >> t;
    while (t--)
        solve();
    return 0;
}