#include <bits/stdc++.h>
using namespace std;

#define FOR(a,b,c) for(int a = b; a < c; a++)

int res = 0;
int n , m;
const int N = 1e3 + 7;

string tab[N];
int pre[N][N];

void liczWyn()
{
	FOR(i,0,n)
	{
		int j = m - 2;
		pre[i][m - 1] = 1;
		while(j >= 0)
		{
			if(tab[i][j] == tab[i][j + 1])pre[i][j] = 1 + pre[i][j + 1];
			else pre[i][j] = 1;
			j--;
		}
	}
	
	FOR(j,0,m)
	{
		int g = 0;
		FOR(i,0,n)
		{
			while(g < n && tab[i][j] == tab[g + 1][j] and pre[g + 1][j] >= (g - i + 2) )g++;

			//cout << j << " " << i << " " << g << endl;
			res += g - i;
		}
	}

}

int main()
{
	//ios_base::sync_with_stdio(0);
	//cout << "LICZ KURWO" << endl;
	cin >> n >> m;
	FOR(i,0,n)cin >> tab[i];
	//cout << "JAZDA\n";
	liczWyn();

	FOR(i,0,n)reverse(tab[i].begin(),tab[i].end());
	liczWyn();
	FOR(i,0,n)reverse(tab[i].begin(),tab[i].end());

	reverse(tab,tab + n);
	//cout << "JAZDA2\n";
	liczWyn();
	
	FOR(i,0,n)reverse(tab[i].begin(),tab[i].end());
	liczWyn();

	cout << res;
	return 0;
}