#include <bits/stdc++.h>

using namespace std;
const int N = 110;
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};

struct Node {
    int x, y;
} b[N];
int bl;

char a[N][N];
int n, m;
vector<string> path;
int res;

void dfs(int u, int sum) {
    if (u == bl + 1) {
        if (sum > res) path.clear();
        if (sum >= res) {
            string t = "";
            for (int i = 1; i <= n; i++)
                for (int j = 1; j <= m; j++)
                    t += a[i][j];
            path.push_back(t);
        }
        res = max(res, sum);
        return;
    }

    dfs(u + 1, sum);

    int f = 1;

    Node c[N];
    int cl = 0;

    int cx = b[u].x, cy = b[u].y;
    for (int i = 0; i < 4; i++) {
        int tx = dx[i] + cx, ty = dy[i] + cy;
        if (tx <= 0 || tx > n || ty <= 0 || ty > m) continue;
        if (a[tx][ty] == 'C' || a[tx][ty] == 'D' || a[tx][ty] == 'Z') return;
        c[++cl] = {tx, ty};
    }

    if (f) {
        a[cx][cy] = 'Z';
        for (int i = 1; i <= cl; i++) a[c[i].x][c[i].y] += 2;

        dfs(u + 1, sum + cl + 1);

        a[cx][cy] = 'B';
        for (int i = 1; i <= cl; i++) a[c[i].x][c[i].y] -= 2;
    }
}

int main() {
    freopen("5.in", "r", stdin);

    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
            if (a[i][j] == 'B') b[++bl] = {i, j};
        }

    dfs(1, 0);

    cout << res << endl;

    for (int i = 0; i < (int)path.size(); i++) {
        for (int j = 0; j < (int)path[i].size(); j++) {
            cout << path[i][j] << " ";
            if ((j + 1) % m == 0) cout << endl;
        }
        cout << endl;
    }

    return 0;
}