#include <bits/stdc++.h>
using namespace std;
const int N = 31;
char a[N][N];
int n, m, cnt;

int main() {
    cin >> n >> m;
    for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
        cin >> a[i][j];
    for (int e = 2; e <= min(m, n);e++){
        for (int i = 0; i <= n - e;i++){
            for (int j = 0; j <= m - e;j++){
                bool f = true;
                for (int x = 0; x < e;x++){
                    for (int y = 0; y < e;y++){
                        if(a[i][j]!=a[i+x][j+y]){
                            f = false;
                            break;
                        }
                    }
                    if (!f) break;
                }
                if (f) cnt++;
            }
        }
    }
    cout << cnt << endl;
    return 0;
}