#include <iostream>
#include <cstdio>
using namespace std;

int tab[1001][1001];
char mapa2[1001][1001];
char mapa[1001][1001];

void obroc( int n )
{
    for ( int i = 1; i <= n; ++i )
    {
        for ( int j = 1; j <= n; ++j )
        {
            mapa2[j][n-i+1] = mapa[i][j];
        }
    }
    for ( int i = 1; i <= n; ++i )
    {
        for ( int j = 1; j <= n; ++j )
        {
            mapa[i][j] = mapa2[i][j];
        }
    }
}


int main()
{
    int n, m;
    scanf( "%d%d", &n, &m );

    for ( int i = 1; i <= n; ++i )
    {
        for ( int j = 1; j <= m; ++j )
        {
            cin >> mapa[i][j];
        }
    }

    int combo;
    char last;
    int answer = 0;
    int xd;

    for ( int q = 0; q < 4; ++q )
    {
        xd = 0;

        /*for ( int i = 1; i <= n; ++i )
        {
            for ( int j = 1; j <= m; ++j )
            {
                cout << mapa[i][j];
            }
            cout << endl;
        }*/

        for ( int i = 1; i <= n; ++i )
        {
            combo = 0; last = 0;
            for ( int j = 1; j <= m; ++j )
            {
                if ( mapa[i][j] == last )
                {
                    combo++;
                }
                else
                {
                    combo = 1;
                    last = mapa[i][j];
                }

                tab[i][j] = 1;

                if ( mapa[i-1][j-1] == mapa[i][j] )
                {
                    tab[i][j] = min( combo, tab[i-1][j-1]+1 );
                    answer += tab[i][j]-1;
                    xd += tab[i][j]-1;
                }
                //cout << tab[i][j];
            }
            //cout << endl;
        }
        //cout << "\t" << xd << endl;
        obroc( max( n, m ) );
        swap( n, m );

    }

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