#include<bits/stdc++.h>
#include"testlib.h"
using namespace std;
using ll = long long;

const ll HWmin = 1, HWmax = 1'000'000;

int main(){
    registerValidation();
    ll H = inf.readLong(HWmin,HWmax);
    inf.readSpace();
    ll W = inf.readLong(HWmin,HWmax);
    inf.readEoln();
    inf.ensuref(H*W <= HWmax,"H x W > 1'000'000");
    for (ll i = 0; i < H; i++){
        string s = inf.readString();
        inf.ensuref((ll)(s.size()) == W, "S[i] size is not W");
        for (auto c : s){
            inf.ensuref(c == '#' || c == '.', "S[i][j] must be '#' or '.'");
        }
    }
    inf.readEof();
}