#include <cstdio>
#include <cstdlib>
#include <ctime>

#include <cstring>
#include <string>
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;

#ifdef KVARK
#define dbg(x) cout << #x << " = " << (x) << endl
#define dbg2(x, y) cout << #x << " = " << (x) << "; " << #y << " = " << y << endl
#else
#define dbg(x) (void(1))
#define dbg2(x, y) (void(1))
#endif

typedef long long llint;
typedef vector<int> vi;
typedef pair<int, int> pii;
#define ALL(v) ((v).begin()), ((v).end())

void task();

int main() {
#ifdef KVARK
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
#endif
    task();
}

const int N = 3e5 + 10;

struct DSU {
    vi a;
    DSU() {
        a.resize(100 * 100 + 10000);
        for (int i = 0; i < a.size(); ++i)
            a[i] = i;
    }

    int get(int i) {
        if (a[i] == i)
            return i;
        return a[i] = get(a[i]);
    }

    void link(int f, int s) {
        f = get(f);
        s = get(s);
        a[f] = s;
    }

    int get(int i, int j) {
        return get(i * 100 + j);
    }

    void link(int i1, int j1, int i2, int j2) {
        link(i1 * 100 + j1, i2 * 100 + j2);
    }
} dsu;

int n, m;
string grid[100];
int used[100][100];
int di[4] = { 0, 0, 1, -1 };
int dj[4] = { -1, 1, 0, 0 };

int isOk(int i, int j) {
    return i >= 0 && i < n && j >= 0 && j < m;
}

void bfs1() {
    memset(used, 0, sizeof(used));
    queue<pii> q;
    int ok = 0;
    for (int i = 0; i < n && !ok; ++i)
        for (int j = 0; j < m; ++j)
            if (grid[i][j] == '.') {
                q.push(pii{ i, j });
                used[i][j] = 1;
                ok = 1;
                break;
            }
    while (!q.empty()) {
        int i = q.front().first;
        int j = q.front().second;
        q.pop();
        for (int h = 0; h < 4; ++h) {
            int ii = i + di[h];
            int jj = j + dj[h];
            if (isOk(ii, jj) && grid[ii][jj] != '#' && !used[ii][jj]) {
                used[ii][jj] = 1;
                q.push(pii{ ii, jj });
            }
        }
    }
}

int used2[51][51];
int bfs2(int I, int J) {
    memset(used2, 0, sizeof(used2));
    queue<pii> q;
    int ok = 0;
    for (int i = 0; i < n && !ok; ++i)
        for (int j = 0; j < m; ++j)
            if (grid[i][j] == '.') {
                q.push(pii{ i, j });
                used2[i][j] = 1;
                ok = 1;
                break;
            }
    while (!q.empty()) {
        int i = q.front().first;
        int j = q.front().second;
        q.pop();
        for (int h = 0; h < 4; ++h) {
            int ii = i + di[h];
            int jj = j + dj[h];
            if (isOk(ii, jj) && grid[ii][jj] != '#' && !used2[ii][jj]) {
                if (ii == I && jj == J) {
                    continue;
                }
                used2[ii][jj] = 1;
                q.push(pii{ ii, jj });
            }
        }
    }
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            if (used2[i][j] == 0 && grid[i][j] == '.') {
                return 0;
            }
    return 1;
}

void task() {
    cin >> n >> m;
    for (int i = 0; i < n; ++i)
        cin >> grid[i];
    bfs1();
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            if (used[i][j] == 0 && grid[i][j] == '.') {
                printf("Impossible");
                return;
            }
    int c = 0;
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            if (grid[i][j] == '?' && used[i][j]) {
                c += bfs2(i, j);
                if (c) {
                    printf("Ambiguous");
                    exit(0);
                }
            }
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j)
            if (grid[i][j] == '?')
                printf("%c", used[i][j] ? '.' : '#');
            else
                printf("%c", grid[i][j]);
        printf("\n");
    }
}