// Author: wlzhouzhuan
#include<bits/stdc++.h>
using namespace std;

#define rep(i,l,r) for(int i=(l);i<=(r);i++)
#define per(i,l,r) for(int i=(l);i>=(r);i--)
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define mset(s,t) memset(s,t,sizeof(s))
#define mcpy(s,t) memcpy(s,t,sizeof(t))
#define SZ(x) ((int)x.size())
#define pb push_back
#define eb emplace_back
#define fir first
#define sec second

template<class T1,class T2>bool ckmax(T1 &a,T2 b){if(a<b)return a=b,1;else return 0;}
template<class T1,class T2>bool ckmin(T1 &a,T2 b){if(a>b)return a=b,1;else return 0;}

inline int read(){
    int x=0,f=0;char ch=getchar();
    while(!isdigit(ch))f|=ch=='-',ch=getchar();
    while(isdigit(ch))x=10*x+ch-'0',ch=getchar();
    return f?-x:x;
}
template<typename T>void print(T x){
    if(x<0)putchar('-'),x=-x;
    if(x>=10)print(x/10);
    putchar(x%10+'0');
}
template<typename T>void print(T x,char ch){
    print(x),putchar(ch);
}

char _[2005][2005],a[2005][2005];
ll ans;

#define left leftt
#define right rightt
int up[2005][2005],down[2005][2005],left[2005][2005],right[2005][2005];
int coefL[2005][2005],coefR[2005][2005];

int iter=0;
void solve(int x1,int x2,int y1,int y2){
    int n=x2-x1+1,m=y2-y1+1;
    if(n<=1||m<=1)return;
    int rot=0;
    if(n>m){
        rep(i,y1,y2)rep(j,x1,x2)a[i-y1][j-x1]=_[j][i];
        swap(n,m);
        rot=1;
    }else{
        rep(i,x1,x2)rep(j,y1,y2)a[i-x1][j-y1]=_[i][j];
        rot=0;
    }
/*    
    if(++iter>=50)return;
    printf("now solve:\n");
    rep(i,0,n-1){
        rep(j,0,m-1)putchar(a[i][j]);
        putchar('\n');
    }
    system("pause");
*/
    rep(i,0,n-1){
        rep(j,0,m-1)left[i][j]=(j&&a[i][j]==a[i][j-1]?left[i][j-1]:j);
        per(j,m-1,0)right[i][j]=(j<m-1&&a[i][j]==a[i][j+1]?right[i][j+1]:j);
    }
    rep(j,0,m-1){
        rep(i,0,n-1)up[i][j]=(i&&a[i][j]==a[i-1][j]?up[i-1][j]:i);
        per(i,n-1,0)down[i][j]=(i<n-1&&a[i][j]==a[i+1][j]?down[i+1][j]:i);
    }
    int mid=m/2-1;
    { // left
        vector d1(n,vector<int> (n)),d2(n,vector<int> (n));
        rep(i,0,n-1){
            int l=left[i][mid],r=mid;
            rep(j,l,r){
                d1[i][i]++;if(down[i][j]<n-1)d1[i][down[i][j]+1]--;
                d2[i][i]++;if(up[i][j]>0)d2[i][up[i][j]-1]--;
            }
            rep(j,1,n-1)d1[i][j]+=d1[i][j-1];
            per(j,n-2,0)d2[i][j]+=d2[i][j+1];
        }
        rep(i,0,n-1){
            rep(j,i+1,n-1){
                if(left[i][mid]>=left[j][mid])coefL[i][j]=d1[i][j];
                else coefL[i][j]=d2[j][i];
            }
        }
    }
    { // right
        vector d1(n,vector<int> (n)),d2(n,vector<int> (n));
        rep(i,0,n-1){
            int l=mid+1,r=right[i][mid+1];
            rep(j,l,r){
                d1[i][i]++;if(down[i][j]<n-1)d1[i][down[i][j]+1]--;
                d2[i][i]++;if(up[i][j]>0)d2[i][up[i][j]-1]--;
            }
            rep(j,1,n-1)d1[i][j]+=d1[i][j-1];
            per(j,n-2,0)d2[i][j]+=d2[i][j+1];
        }
        rep(i,0,n-1){
            rep(j,i+1,n-1){
                if(right[i][mid+1]<=right[j][mid+1])coefR[i][j]=d1[i][j];
                else coefR[i][j]=d2[j][i];
            }
        }
    }
    // combine
    rep(i,0,n-1){
        rep(j,i+1,n-1){
            if(a[i][mid]==a[i][mid+1]&&a[j][mid]==a[j][mid+1]&&a[i][mid]==a[j][mid]){
                ans+=1ll*coefL[i][j]*coefR[i][j];
            }
        }
    }
    if(rot){
        solve(x1,x1+mid,y1,y2);
        solve(x1+mid+1,x2,y1,y2);
    }else{
        solve(x1,x2,y1,y1+mid);
        solve(x1,x2,y1+mid+1,y2);
    }
}

int main(){
    int n=read(),m=read();
    rep(i,0,n-1)scanf("%s",_[i]);
    solve(0,n-1,0,m-1);
    print(ans,'\n');
    return 0;
}