#include<iostream>
#include<cstring>
#include<vector>
#include<algorithm>
using namespace std;
using LL = long long;
char g[1005][1005];
int dir[1005][1005];
int n, m;

// UDLR
const int dx[4]{-1, 1, 0, 0};
const int dy[4]{0, 0, -1, 1};

void solve(int x, int y, int type, char c){
    if (x <= 0 or x > n or y <= 0 or y > m){
        cout << "NO" << '\n';
        exit(0);
    }
    if (dir[x][y] == -1){
        if (g[x][y] == '.'){
            solve(x + dx[type], y + dy[type], type, c);
        }
        else if (g[x][y] != c){
            cout << "NO" << '\n';
            exit(0);
        }
        return;
    }
    if (g[x][y] == '.'){
        g[x][y] = c;
        dir[x][y] = type;
        return;
    }
    if (g[x][y] == c){
        dir[x][y] = -1;
        return;
    }
    int bk = dir[x][y];
    char bkc = g[x][y];
    dir[x][y] = -1;
    g[x][y] = '.';
    solve(x + dx[type], y + dy[type], type, c);
    solve(x + dx[bk], y + dy[bk], bk, bkc);
}

int main(){

#ifdef LOCAL
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif

    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);

    cin >> n >> m;
    for(int i = 0; i <= n + 1; i++){
        for(int j = 0; j <= m + 1; j++){
            cin >> g[i][j];
            if (g[i][j] == 'x') dir[i][j] = -1;
        }
    }
    for(int i = 1; i <= m; i++){
        if (g[0][i] != '.') solve(1, i, 0, g[0][i]);
        if (g[n + 1][i] != '.') solve(n, i, 1, g[n + 1][i]);
    }
    for(int i = 1; i <= n; i++){
        if (g[i][0] != '.') solve(i, 1, 2, g[i][0]);
        if (g[i][m + 1] != '.') solve(i, m, 3, g[i][m + 1]);
    }
    cout << "YES" << '\n';
    for(int i = 1; i <= n; i++){
        replace(g[i] + 1, g[i] + m + 1, 'x', '.');
        for(int j = 1; j <= m; j++){
            cout << g[i][j];
        }
        cout << '\n';
    }

}