#include <iostream>
#include <vector>
#include <cstdlib>
#include <cstdio>
#include <set>
using namespace std;
using LL = long long;
int t[1008][1008];
int t1[1008][1008];
int t2[1008][1008];
int t3[1008][1008];
int t4[1008][1008];
int jobbra[1008][1008];


LL szamol(int n, int m) {
	/*for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			cout << (char)t[i][j] << " ";
		}
		cout << endl;
		
	}*/
	
	for (int i = 0; i < n; i++){
		jobbra[i][m-1] = 1;
		for (int j = m-2; j >= 0 ; j--){
			jobbra[i][j] = (t[i][j] == t[i][j+1] ? 1+jobbra[i][j+1] : 1);
		}
	}
	
	//cout << "jobbra: " << endl;
	/*for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			cout << jobbra[i][j] << " ";
		}
		cout << endl;
	}*/
	
	
	LL ans = 0LL;
	for (int j = 0; j < m; j++){
		LL curr = 1LL;
		for (int i = n-2; i >= 0; i--){
			if (t[i][j] == t[i+1][j]) {
				curr = min(curr+1LL, (LL)jobbra[i][j]);
			}
			else {
				curr = 1LL;
			}
			/*if (jobbra[i][j] > curr && t[i][j] == t[i+1][j]) {
				curr++;
			}
			else {
				curr = 1LL;
			}*/
			ans += curr-1;
			//cout << i << " " << j << " " << curr << " " << ans << "   " << (char)t[i][j] << " " << (char)t[i+1][j] << endl;
		}
		
	}
	return ans;
}

int main() {
	
	int n,m;
	//scanf("%d %d", &n, &m);
	cin>>n>>m;
	
	for (int i = 0; i < n; i++){
		string s;
		cin>>s;
		for (int j = 0; j < m; j++){
			t1[i][j] = int(s[j]);
			t2[j][n-1-i] = int(s[j]);
			t3[n-1-i][m-1-j] = int(s[j]);
			t4[m-1-j][i] = int(s[j]);
			
		}
	}
	
	//cout << "elso" << endl;
	LL ans = 0;
	for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			t[i][j] = t1[i][j];
		}
	}
	/*for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			cout << (char)t[i][j] << " ";
		}
		cout << endl;
	}*/
	ans += szamol(n,m);
	
	//cout << "masodik" << endl;
	for (int i = 0; i < m; i++){
		for (int j = 0; j < n; j++){
			t[i][j] = t2[i][j];
		}
	}
	/*for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			cout << (char)t[i][j] << " ";
		}
		cout << endl;
	}*/
	ans += szamol(m,n);
	
	//cout << "harmadik" << endl;
	for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			t[i][j] = t3[i][j];
		}
	}
	/*for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			cout << (char)t[i][j] << " ";
		}
		cout << endl;
	}*/
	ans += szamol(n,m);
	
	//cout << "negyedik" << endl;
	for (int i = 0; i < m; i++){
		for (int j = 0; j < n; j++){
			t[i][j] = t4[i][j];
		}
	}
	/*for (int i = 0; i < m; i++){
		for (int j = 0; j < n; j++){
			cout << (char)t[i][j] << " ";
		}
		cout << endl;
	}*/
	ans += szamol(m,n);
	
	cout << ans << endl;
	
	return 0;
}