#include <bits/stdc++.h>
#define LL long long
using namespace std;
char mp[2005][2005];
struct MatGeter{
	int x,y,n,m,flg;
	void init(int x1,int y1,int x2,int y2,int flg_){
		x=x1,y=y1,flg=flg_;
		n=x2-x1+1,m=y2-y1+1;
	}
	char operator()(int i,int j){
		if(flg) swap(i,j);
		if(i>=n||j>=m||i<0||j<0) return 0;
		return mp[i+x][j+y];
	}
}mt;
int u[2005][2005],d[2005][2005],l[2005][2005],r[2005][2005];
int cntl[2005][2005],cntr[2005][2005];
LL ans=0;
void solve(int x1,int y1,int x2,int y2){
	int n=x2-x1+1,m=y2-y1+1;
	if(n<=1||m<=1) return;
	mt.init(x1,y1,x2,y2,n>m);
	if(n>m) swap(n,m);
	for(int i=0;i<n;i++)
	for(int j=0;j<m;j++){
		if(mt(i,j)==mt(i-1,j)) u[i][j]=u[i-1][j]+1;
		else u[i][j]=1;
		if(mt(i,j)==mt(i,j-1)) l[i][j]=l[i][j-1]+1;
		else l[i][j]=1;
	}
	for(int i=n-1;i>=0;i--)
	for(int j=m-1;j>=0;j--){
		if(mt(i,j)==mt(i+1,j)) d[i][j]=d[i+1][j]+1;
		else d[i][j]=1;
		if(mt(i,j)==mt(i,j+1)) r[i][j]=r[i][j+1]+1;
		else r[i][j]=1;
	}
	int mid=((m-1)>>1);
	for(int i=0;i<n;i++)
	for(int j=0;j<n;j++){
		cntl[i][j]=cntr[i][j]=0;
	}
	for(int i=0;i<n;i++){
		for(int j=mid-l[i][mid]+1;j<=mid;j++){
			cntl[i][i-u[i][j]+1]++;
			cntl[i][i+d[i][j]]--;
		}
		for(int j=mid+1;j<=mid+r[i][mid+1];j++){
			cntr[i][i-u[i][j]+1]++;
			cntr[i][i+d[i][j]]--;
		}
		for(int j=0;j<n;j++){
			cntl[i][j]+=cntl[i][j-1];
			cntr[i][j]+=cntr[i][j-1];
		}
	}
	for(int i=0;i<n;i++)
	for(int j=i+1;j<n;j++){
		int val1,val2;
		if(l[i][mid]<l[j][mid]) val1=cntl[i][j];
		else val1=cntl[j][i];
		if(r[i][mid+1]<r[j][mid+1]) val2=cntr[i][j];
		else val2=cntr[j][i];
		ans+=1ll*val1*val2;
	}
	if(mt.flg){
		int mid=(x1+x2)>>1;
		solve(x1,y1,mid,y2);
		solve(mid+1,y1,x2,y2);
	}
	else{
		int mid=(y1+y2)>>1;
		solve(x1,y1,x2,mid);
		solve(x1,mid+1,x2,y2);
	}
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n,m;
	cin>>n>>m;
	for(int i=0;i<n;i++)
	for(int j=0;j<m;j++)
		cin>>mp[i][j];
	solve(0,0,n-1,m-1);
	cout<<ans<<'\n';
	return 0;
}