#include <bits/stdc++.h>

using namespace std;


const int N = 1111;

int n, m;
char A[N][N];
char B[N][N];

int h[N][N];

int main() {
  scanf("%d%d", &n, &m);
  for(int i = 0; i < n; i++) {
    scanf("%s", A[i]);
  }

  int ans = 0;
  for(int it = 0; it < 4; it++) {


    int prev = 0;
    for(int i = 0; i < n; i++) {
      for(int j = 0; j < m; j++) {
	if(i > 0 && A[i-1][j] == A[i][j]) {
	  h[i][j] = h[i-1][j];
	} else {
	  h[i][j] = i;
	}

	int d = i - h[i][j] + 1;

	if(j > 0 && A[i][j] == A[i][j-1]) {
	  d = min(d, prev + 1);
	} else {
	  d = 1;
	}

	ans += d - 1;
	prev = d;
      }
    }


    // for(int i = 0; i < n; i++) printf("%s\n", A[i]);


    memset(B, 0, sizeof B);
    for(int i = 0; i < m; i++) {
      for(int j = 0; j < n; j++) {
	B[i][j] = A[j][m-i-1];
      }
    }

    swap(n, m);
    memcpy(A, B, sizeof B);

  }

  printf("%d\n", ans);
}