#include <bits/stdc++.h>

#define FOR(n, a, b) for(int n = (a); n < (b); ++n)
#define ALL(x) x.begin(), x.end()
#define pb push_back
#define st first
#define nd second

using namespace std;

const int maxN = 1010;

int n, m;
char T[maxN][maxN];
int pref[maxN][maxN];

bool onbord(int i, int j)
{
    return i >= 0 and i < n and j >= 0 and j < m;
}

pair <int, int> Start(int diag)
{
    if (diag < n)
        return {diag, 0};
    return {n-1, diag-n + 1};
}

void swapp(int i0, int i1)
{
    FOR(j, 0, m)
        swap(T[i0][j], T[i1][j]);
}

void swapp2(int j0, int j1)
{
    FOR(i, 0, n)
        swap(T[i][j0], T[i][j1]);
}

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

    FOR(i, 0, n)
        scanf ("%s", T[i]);

    long long res = 0;

    FOR(step, 0, 2)
    {
        FOR(step2, 0, 2)
        {
            FOR(i, 0, n) FOR(j, 1, m)
                pref[i][j] = T[i][j] == T[i][j - 1] ? pref[i][j- 1] : j;

            FOR(diag, 0, n+m-1)
            {
                int len = 0, i, j;
                for (tie(i, j) = Start(diag); onbord(i, j); i--, j++)
                {
                    //printf("diag=%d, i=%d, j=%d;  ", diag, i, j);
                    while (onbord(i - (len+1), j + (len+1)) and T[i][j] == T[i - (len+1)][j + (len+1)] and pref[i - (len+1)][j + (len+1)] <= j)
                        len++;

                    //printf("len = %d;\n", len);
                    res += len;
                    len--;
                }
            }

            FOR(j, 0, m/2)
                swapp2(j, m-1-j);
        }

        FOR(i, 0, n/2)
            swapp(i, n-1-i);
    }

    printf("%lld\n", res);
    return 0;
}