#include<stdio.h>
#include<string.h>
#include<algorithm>
#define MAXN 25
#define MAXD 410
int dx[] = {-1, 1, 0, 0}, dy[] = {0, 0, -1, 1}, L;
int N, M, a[MAXN][MAXN];
struct List
{int x, y;
}list[MAXD];
void init()
{int i, j;char b[MAXN];for(i = N - 1; i >= 0; i --){scanf("%s", b);for(j = 0; j < M; j ++) a[i][j] = b[j] - '0';}
}
struct St
{int N, M, g[MAXN][MAXN], cnt[MAXD], col[MAXN][MAXN];void init(int N, int M, int g[][MAXN]){this->N = N, this->M = M;memcpy(this->g, g, sizeof(this->g));}inline int inside(int x, int y){return x >= 0 && x < N && y >= 0 && y < M;}void color(int x, int y, int &cnt, int c){int i, nx, ny;col[x][y] = c, ++ cnt;for(i = 0; i < 4; i ++){nx = x + dx[i], ny = y + dy[i];if(inside(nx, ny) && g[nx][ny] == g[x][y] && !col[nx][ny])color(nx, ny, cnt, c);}}void erase(int x, int y){int i, nx, ny;g[x][y] = 0;for(i = 0; i < 4; i ++){nx = x + dx[i], ny = y + dy[i];if(inside(nx, ny) && col[x][y] == col[nx][ny] && g[nx][ny])erase(nx, ny);}}inline int find(int j){for(int i = 0; i < N; i ++) if(g[i][j]) return 0;return 1;}void arrange(){int i, j, k, kmax;kmax = 0;for(j = 0; j < M; j ++){k = 0;for(i = 0; i < N; i ++)if(g[i][j]){if(i != k)g[k][j] = g[i][j], g[i][j] = 0;++ k;}kmax = std::max(kmax, k);}N = kmax;k = 0;for(j = 0; j < M; j ++)if(!find(j)){if(j != k) for(i = 0; i < N; i ++) g[i][k] = g[i][j];++ k;}M = k;}int gogo(){int i, j, ans = 0, max, x, y, c;for(;;){max = c = 0;for(i = 0; i < N; i ++)for(j = 0; j < M; j ++) col[i][j] = 0;for(i = N - 1; i >= 0; i --)for(j = 0; j < M; j ++)if(g[i][j] && !col[i][j]){++ c, cnt[c] = 0;color(i, j, cnt[c], c);if(cnt[c] > max) max = cnt[c], x = i, y = j;}if(max <= 1) break;ans += (max - 1) * max;erase(x, y), arrange();}return ans;}
};
void solve()
{St st;st.init(N, M, a);printf("%d\n", st.gogo());
}
int main()
{while(scanf("%d%d", &N, &M) == 2){init();solve();}return 0;
}
/*
Sample Input:5 5
32345
32345
32345
32345
121115 5
32223
32213
32223
32221
12111Sample Output:112
204*/