#include<bits/stdc++.h>
#define ll long long
using namespace std;
inline int read(){
    char ch=getchar();int x=0;bool f=1;
    while(ch<'0'||'9'<ch){if(ch=='-')f=0;ch=getchar();}
    while('0'<=ch&&ch<='9'){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
    return f?x:-x;
}
const int N=2502;
mt19937 rnd(3183);
int n,m,U[N][N],D[N][N],L[N][N],R[N][N],pre[N][N],suf[N][N];
char s[N][N],c[N][N];
ll ans;
void solve(int u,int d,int l,int r){
    if(l==r||u==d)return;
    if(r-l>=d-u){
        int mid=(l+r)>>1;
        solve(u,d,l,mid);solve(u,d,mid+1,r);
        for(int i=u;i<=d;i++)
            for(int j=u;j<=d;j++)pre[i][j]=suf[i][j]=0;
        for(int i=u;i<=d;i++){
            for(int j=mid;j>=l&&j>=L[i][mid];j--)
                pre[i][min(D[i][j],d)]++,pre[i][max(U[i][j],u)]++;
            for(int j=d-1;j>=i;j--)pre[i][j]+=pre[i][j+1];
            for(int j=u+1;j<=i;j++)pre[i][j]+=pre[i][j-1];
            for(int j=mid+1;j<=r&&j<=R[i][mid+1];j++)
                suf[i][min(D[i][j],d)]++,suf[i][max(U[i][j],u)]++;
            for(int j=d-1;j>=i;j--)suf[i][j]+=suf[i][j+1];
            for(int j=u+1;j<=i;j++)suf[i][j]+=suf[i][j-1];
        }
        for(int i=u;i<=d;i++)
            for(int j=i+1;j<=d;j++)
                if(s[i][mid]==s[j][mid]&&s[i][mid]==s[i][mid+1]&&s[i][mid]==s[j][mid+1]){
                    int cntL=L[i][mid]>=L[j][mid]?pre[i][j]:pre[j][i];
                    int cntR=R[i][mid+1]<=R[j][mid+1]?suf[i][j]:suf[j][i];
                    ans+=1ll*cntL*cntR;
                }
    }
    else{
        int mid=(u+d)>>1;
        solve(u,mid,l,r);solve(mid+1,d,l,r);
        for(int i=l;i<=r;i++)
            for(int j=l;j<=r;j++)pre[i][j]=suf[i][j]=0;
        for(int i=l;i<=r;i++){
            for(int j=mid;j>=u&&j>=U[mid][i];j--)
                pre[i][min(R[j][i],r)]++,pre[i][max(L[j][i],l)]++;
            for(int j=r-1;j>=i;j--)pre[i][j]+=pre[i][j+1];
            for(int j=l+1;j<=i;j++)pre[i][j]+=pre[i][j-1];
            for(int j=mid+1;j<=d&&j<=D[mid+1][i];j++)
                suf[i][min(R[j][i],r)]++,suf[i][max(L[j][i],l)]++;
            for(int j=r-1;j>=i;j--)suf[i][j]+=suf[i][j+1];
            for(int j=l+1;j<=i;j++)suf[i][j]+=suf[i][j-1];
        }
        for(int i=l;i<=r;i++)
            for(int j=i+1;j<=r;j++)
                if(s[mid][i]==s[mid][j]&&s[mid][i]==s[mid+1][i]&&s[mid][i]==s[mid+1][j]){
                    int cntL=U[mid][i]>=U[mid][j]?pre[i][j]:pre[j][i];
                    int cntR=D[mid+1][i]<=D[mid+1][j]?suf[i][j]:suf[j][i];
                    ans+=1ll*cntL*cntR;
                }
    }
}
signed main(){
    // freopen(".in","r",stdin);
    // freopen(".out","w",stdout);
    n=read();m=read();
    for(int i=1;i<=n;i++)
        scanf("%s",s[i]+1);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            U[i][j]=(s[i][j]==s[i-1][j]?U[i-1][j]:i),
            L[i][j]=(s[i][j]==s[i][j-1]?L[i][j-1]:j);
    for(int i=n;i;i--)
        for(int j=m;j;j--)
            D[i][j]=(s[i][j]==s[i+1][j]?D[i+1][j]:i),
            R[i][j]=(s[i][j]==s[i][j+1]?R[i][j+1]:j);
    solve(1,n,1,m);
    printf("%lld\n",ans);
    return 0;
}