#include <iostream>
#include <vector>
#define PB push_back
#define F first
#define B back

using namespace std;

typedef long long int ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;

const ll asci_codes=100, W=1010, H=1010;

ll up[asci_codes][H][W], down[asci_codes][H][W];
char input[H][W];

int main(int argc, char const *argv[]) {
  ll n, m;
  cin >> n >> m;

  for (ll i = 0; i < n; ++i) {
    for (ll j = 0; j < m; ++j) {
      cin >> input[i][j];
      input[i][j] -= 33;
    }
  }

  for (ll j = 0; j < m; ++j) {
    for (ll code = 0; code < asci_codes; ++code) {
      if (code == input[0][j]) {
        up[code][0][j] = 1;
      } else {
        up[code][0][j] = 0;
      }

      for (ll i = 1; i < n; ++i) {
        if (code == input[i][j]) {
          up[code][i][j] = up[code][i-1][j]+1;
        } else {
          up[code][i][j] = 0;
        }
      }

      if (code == input[n-1][j]) {
        down[code][n-1][j] = 1;
      } else {
        down[code][n-1][j] = 0;
      }

      for (ll i = n-2; i >= 0; --i) {
        if (code == input[i][j]) {
          down[code][i][j] = down[code][i+1][j]+1;
        } else {
          down[code][i][j] = 0;
        }
      }
    }
  }

/*
  for (ll i = 0; i < n; ++i) {
    for (ll j = 0; j < m; ++j) {
      cout << down['#'-33][i][j] << " ";
    }
    cout << "\n";
  }
*/
  ll lu = 0, ld = 0, ru = 0, rd = 0;
  for (ll code = 0; code < asci_codes; ++code) {
    for (ll i = 0; i < n; ++i) {
      ll h = 0;
      ll d = 0;
      for (ll j = 0; j < m; ++j) {
        if (h >= up[code][i][j]) {
          h = up[code][i][j];
        } else {
          ++h;
        }
        if (h > 1) lu += h-1;

        if (d >= down[code][i][j]) {
          d = down[code][i][j];
        } else {
          ++d;
        }
        if (d > 1) ld += d-1;
      }
    }


    for (ll i = 0; i < n; ++i) {
      ll h = 0;
      ll d = 0;
      for (ll j = m-1; j >= 0; --j) {
        if (h >= up[code][i][j]) {
          h = up[code][i][j];
        } else {
          ++h;
        }
        if (h > 1) ru += h-1;

        if (d >= down[code][i][j]) {
          d = down[code][i][j];
        } else {
          ++d;
        }
        if (d > 1) rd += d-1;
      }
    }
  }
  ll s = ld+lu+rd+ru;
	
  //cout <<  ld << " " <<  lu << " " <<  rd << " " << ru << "\n"; 
  cout << s << endl;

  return 0;
}