#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl '\n'
#define m3lsh return 0;
typedef long long ll;
typedef unsigned long long ull;

ll gcd(ll a, ll b) { return !b ? a : gcd(b, a % b); }
ll lcm(ll a, ll b) { return (a / gcd(a, b)) * b; }

int  dix[] = { 1, -1, 0, 0, 1, 1, -1, -1 };
int  diy[] = { 0, 0, 1, -1, 1, -1, 1, -1 };
int main() {
    fast;
    char grid[100][100];
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            cin >> grid[i][j];
    bool ok = 0;
    string ch = "bay";
    for (int i = 0; i < n; i++) {
        string procss = "";
        for (int j = 0; j < m - 2; j++) {
            procss = char(grid[i][j]);
            procss += char(grid[i][j + 1]);
            procss += char(grid[i][j + 2]);
            if (procss == ch)ok = 1;
            reverse(procss.begin(), procss.end());
            if (procss == ch)ok = 1;
        }
    }
    for (int i = 0; i < m; i++) {
        string procss = "";
        for (int j = 0; j < n - 2; j++) {
            procss = grid[j][i];
            procss += grid[j + 1][i];
            procss += grid[j + 2][i];
            if (procss == ch)ok = 1;
            reverse(procss.begin(), procss.end());
            if (procss == ch)ok = 1;
        }
    }
    for (int i = 0; i < min(n, m) - 2; i++) {
        string procss = "";
        procss = grid[i][i];
        procss += grid[i + 1][i + 1];
        procss += grid[i + 2][i + 2];
        if (ch == procss)ok = 1;
        reverse(procss.begin(), procss.end());
        if (procss == ch)ok = 1;
    }
    int row = 0;
    for (int i = m - 1; i >= 2; i--) {
        string procss = "";
        if (row < n - 2) {
            procss = grid[row][i];
            procss += grid[row + 1][i - 1];
            procss += grid[row + 2][i - 2];
            if (procss == ch)ok = 1;
            reverse(procss.begin(), procss.end());
            if (ch == procss)ok = 1;
            row--;
        }
    }
    if (ok)cout << "YES" << endl;
    else cout << "NO" << endl;
    m3lsh;
}