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

int main(int argc, char* argv[]) {
    registerValidation(argc, argv);
    int h = inf.readInt(1, 10, "h");
    inf.readSpace();
    int w = inf.readInt(1, 10, "w");
    inf.readEoln();
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            char c = inf.readChar();
            assert(c == '.' || c == '#');
        }
        inf.readEoln();
    }
    inf.readEof();
    cout << "No" << endl;
    return 0;
}