#pragma GCC optimize(3)
  #pragma GCC target("avx,sse2,sse3,sse4,mmx")
  #pragma GCC optimize("Ofast")
  #pragma GCC optimize("inline")
  #pragma GCC optimize("-fgcse")
  #pragma GCC optimize("-fgcse-lm")
  #pragma GCC optimize("-fipa-sra")
  #pragma GCC optimize("-ftree-pre")
  #pragma GCC optimize("-ftree-vrp")
  #pragma GCC optimize("-fpeephole2")
  #pragma GCC optimize("-ffast-math")
  #pragma GCC optimize("-fsched-spec")
  #pragma GCC optimize("unroll-loops")
  #pragma GCC optimize("-falign-jumps")
  #pragma GCC optimize("-falign-loops")
  #pragma GCC optimize("-falign-labels")
  #pragma GCC optimize("-fdevirtualize")
  #pragma GCC optimize("-fcaller-saves")
  #pragma GCC optimize("-fcrossjumping")
  #pragma GCC optimize("-fthread-jumps")
  #pragma GCC optimize("-funroll-loops")
  #pragma GCC optimize("-freorder-blocks")
  #pragma GCC optimize("-fschedule-insns")
  #pragma GCC optimize("inline-functions")
  #pragma GCC optimize("-ftree-tail-merge")
  #pragma GCC optimize("-fschedule-insns2")
  #pragma GCC optimize("-fstrict-aliasing")
  #pragma GCC optimize("-fstrict-overflow")
  #pragma GCC optimize("-falign-functions")
  #pragma GCC optimize("-fcse-skip-blocks")
  #pragma GCC optimize("-fcse-follow-jumps")
  #pragma GCC optimize("-fsched-interblock")
  #pragma GCC optimize("-fpartial-inlining")
  #pragma GCC optimize("no-stack-protector")
  #pragma GCC optimize("-freorder-functions")
  #pragma GCC optimize("-findirect-inlining")
  #pragma GCC optimize("-fhoist-adjacent-loads")
  #pragma GCC optimize("-frerun-cse-after-loop")
  #pragma GCC optimize("inline-small-functions")
  #pragma GCC optimize("-finline-small-functions")
  #pragma GCC optimize("-ftree-switch-conversion")
  #pragma GCC optimize("-foptimize-sibling-calls")
  #pragma GCC optimize("-fexpensive-optimizations")
  #pragma GCC optimize("-funsafe-loop-optimizations")
  #pragma GCC optimize("inline-functions-called-once")
  #pragma GCC optimize("-fdelete-null-pointer-checks")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int, int> PII;

#define fir first
#define sec second
#define ep emplace
#define eb emplace_back

#define lowbit(x) ((x) & (-(x)))

inline int read() {
	int x = 0, f = 1; char ch = getchar();
	for (; !isdigit(ch); ch = getchar()) if (ch == '-') f = -1;
	for (; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + (ch ^ 48);
	return x * f;
}

const int N = 2510, M = 2510;

int n, m, id[N][M], tot;
char g[N][M];
ll ans;

int main() {
	n = read(), m = read();
	for (int i = 1; i <= n; i ++ ) {
		scanf("%s", g[i] + 1);
		for (int j = 1; j <= m; j ++ ) {
			if (g[i][j] == g[i - 1][j]) id[i][j] = id[i - 1][j];
			else id[i][j] = ++ tot;
		}
	}
	for (int i = 1; i <= n; i ++ ) {
		for (int j = i + 1; j <= n; j ++ ) {
			int cnt = 0;
			for (int k = 1; k <= m; k ++ ) {
				if (g[i][k] != g[j][k] || g[i][k - 1] != g[i][k]) cnt = 0;
				if (id[i][k] == id[j][k]) ans += cnt ++ ;
			}
		}
	}
	printf("%lld\n", ans);
	return 0;
}
/*
求极长连续竖段
*/