#include <bits/stdc++.h>
//#define int long long
#define pai 3.141592653589793238462643383279502884197169399375105820
#define MOD 1000000007
#define eps 0.00000001
inline int min(int a,int b) {return a<b?a:b;}
inline int max(int a,int b) {return a>b?a:b;}
#define ULL unsigned long long
#define LL long long
#define INF 0x3f3f3f3f
#define INF_LL 0x3f3f3f3f3f3f3f3f
static char buf[1000000],*paa=buf,*pd=buf;
static char buf2[1000000],*pp=buf2;
#define getchar() paa==pd&&(pd=(paa=buf)+fread(buf,1,1000000,stdin),paa==pd)?EOF:*paa++
inline void pc(char ch){
	if(pp-buf2==1000000) fwrite(buf2,1,1000000,stdout),pp=buf2;
	*pp++=ch;
}
inline void pcc(){
	fwrite(buf2,1,pp-buf2,stdout);
	pp=buf2;
}
inline int read(void) {
	int w=1;
	register int x(0);register char c(getchar());
	while(c<'0'||c>'9') {if(c=='-') w=-1;c=getchar();}
	while(c>='0'&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return w*x;
}
void write(int x) {
	static int sta[20];
	int top=0;
	do {
		sta[top++]=x%10,x/=10;
	} while(x);
	while(top) pc(sta[--top]+48);
}
void we(int x) {
	write(x);
	pc('\n');
}
inline bool cmp_xi(int a,int b) {return a<b;}
inline bool cmp_da(int a,int b) {return a>b;}
int N,M,up[2009][2009],dn[2009][2009],lt[2009][2009],rt[2009][2009];
char s[2009][2009];
signed main(void) {
	//freopen("m.in","r",stdin);
    //freopen("m.out","w",stdout);
	scanf("%d %d",&N,&M);
	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++) {
			if(s[i][j]==s[i-1][j]) up[i][j]=up[i-1][j]+1;else up[i][j]=1;
		}
	}
	for(int i=N;i>=1;i--) {
		for(int j=1;j<=M;j++) {
			if(s[i][j]==s[i+1][j]) dn[i][j]=dn[i+1][j]+1;else dn[i][j]=1;
		}
	}
	for(int i=1;i<=N;i++) {
		for(int j=1;j<=M;j++) {
			if(s[i][j]==s[i][j-1]) lt[i][j]=lt[i][j-1]+1;else lt[i][j]=1;
		}
	}
	for(int i=1;i<=N;i++) {
		for(int j=M;j>=1;j--) {
			if(s[i][j]==s[i][j+1]) rt[i][j]=rt[i][j+1]+1;else rt[i][j]=1;
		}
	}
	LL ans=0;
	for(int i=1;i<=N;i++) {
		for(int j=1;j<=M;j++) {
			for(int k=i+1;k<i+dn[i][j];k++) {
				for(int l=j+1;l<j+rt[i][j];l++) {
					if(s[i][j]==s[k][l]&&k-up[k][l]<i&&l-lt[k][l]<j) {
						ans++;
					}
				}
			}
		}
	}
	printf("%lld",ans);
    return 0;
}