#include <cstdio>
#include <algorithm>
#include <cstring>
#include <iostream>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <ctime>
#include <random>
#include <cassert>
#include <numeric>
#include <cmath>
#include <bitset>
#include <ext/pb_ds/assoc_container.hpp>
#define pii pair<int, int>
#define fi first
#define se second
#define MP make_pair
#define ep emplace
#define eb emplace_back
//#define int long long
#define rep(i, j, k) for (int i = (j); i <= (k); i++)
#define per(i, j, k) for (int i = (j); i >= (k); i--)
typedef double db;
typedef long double ldb;
typedef long long ll;
//typedef __int128 lll;
typedef unsigned long long ull;
typedef unsigned int ui;
using namespace std;
using namespace __gnu_pbds;
bool Mbe;

//char buf[1<<20],*p1,*p2;
//#define getchar() (p1 == p2 && (p2 = (p1 = buf) + fread(buf,1,1<<20,stdin), p1 == p2) ? 0 : *p1++)
int read() {
	int s = 0, f = 1;
	char c = getchar();
	while (c < '0' || c > '9') f ^= (c == '-'), c = getchar();
	while (c >= '0' && c <= '9') s = s * 10 + c - '0', c = getchar();
	return f ? s : -s;
}
template<typename T>void chkmax(T&x,const T&y){if(x<y)x=y;}
template<typename T>void chkmin(T&x,const T&y){if(x>y)x=y;}

const int N=2005;
int n,m,D[N][N],U[N][N],L[N][N],R[N][N],f[N][N],g[N][N];
ll ans;
char s[N][N];
void solve(int u,int d,int l,int r){
	if(u==d||l==r)return;
	rep(i,u,d)rep(j,l,r){
		chkmax(U[i][j],u);
		chkmin(D[i][j],d);
		chkmax(L[i][j],l);
		chkmin(R[i][j],r);
	}
	if(d-u<=r-l){
		rep(i,u,d)rep(j,u,d)f[i][j]=g[i][j]=0;
		int mid=(l+r)>>1;
		rep(i,u,d){
			per(j,mid,L[i][mid])f[i][U[i][j]]++,f[i][D[i][j]]++;
			rep(j,mid+1,R[i][mid])g[i][U[i][j]]++,g[i][D[i][j]]++;
			per(j,d-1,i+1)f[i][j]+=f[i][j+1],g[i][j]+=g[i][j+1];
			rep(j,u+1,i-1)f[i][j]+=f[i][j-1],g[i][j]+=g[i][j-1];
		}
		rep(i,u,d)rep(j,i+1,d)if(s[i][mid]==s[j][mid]){
			int valf=L[i][mid]>=L[j][mid]?f[i][j]:f[j][i];
			int valg=R[i][mid]<=R[j][mid]?g[i][j]:g[j][i];
			ans+=valf*valg;
		}
		solve(u,d,l,mid),solve(u,d,mid+1,r);
	}else{
		rep(i,l,r)rep(j,l,r)f[i][j]=g[i][j]=0;
		int mid=(u+d)>>1;
		rep(j,l,r){
			per(i,mid,U[mid][j])f[j][L[i][j]]++,f[j][R[i][j]]++;
			rep(i,mid+1,D[mid][j])g[j][L[i][j]]++,g[j][R[i][j]]++;
			per(i,r-1,j+1)f[j][i]+=f[j][i+1],g[j][i]+=g[j][i+1];
			rep(i,l+1,j-1)f[j][i]+=f[j][i-1],g[j][i]+=g[j][i-1];
		}
		rep(i,l,r)rep(j,i+1,r)if(s[mid][i]==s[mid][j]){
			int valf=U[mid][i]>=U[mid][j]?f[i][j]:f[j][i];
			int valg=D[mid][i]<=D[mid][j]?g[i][j]:g[j][i];
			ans+=valf*valg;
		}
		solve(u,mid,l,r),solve(mid+1,d,l,r);
	}
}

bool Med;
signed main() {
	fprintf(stderr,"%.3lfMb\n",(&Mbe-&Med)/1024./1024.);
	n=read(),m=read();
	rep(i,1,n)scanf("%s",s[i]+1);
	rep(i,1,n)rep(j,1,m)L[i][j]=(s[i][j]==s[i][j-1])?L[i][j-1]:j;
	rep(i,1,n)per(j,m,1)R[i][j]=(s[i][j]==s[i][j+1])?R[i][j+1]:j;
	rep(j,1,m)rep(i,1,n)U[i][j]=(s[i][j]==s[i-1][j])?U[i-1][j]:i;
	rep(j,1,m)per(i,n,1)D[i][j]=(s[i][j]==s[i+1][j])?D[i+1][j]:i;
	solve(1,n,1,m);
	printf("%lld\n",ans);
	return 0;
}