#include "bits/stdc++.h"

#pragma warning(disable:4996)
using namespace std;


const int mod = 1000000007;
struct Mod {
public:
	int num;
	Mod() : Mod(0) { ; }
	Mod(long long int n) : num((n % mod + mod) % mod) {
		static_assert(mod<INT_MAX / 2, "mod is too big, please make num 'long long int' from 'int'");
	}
	Mod(int n) : Mod(static_cast<long long int>(n)) { ; }
	operator int() { return num; }
};

Mod operator+(const Mod a, const Mod b) { return Mod((a.num + b.num) % mod); }
Mod operator+(const long long int a, const Mod b) { return Mod(a) + b; }
Mod operator+(const Mod a, const long long int  b) { return b + a; }
Mod operator++(Mod &a) { return a + Mod(1); }
Mod operator-(const Mod a, const Mod b) { return Mod((mod + a.num - b.num) % mod); }
Mod operator-(const long long int a, const Mod b) { return Mod(a) - b; }
Mod operator--(Mod &a) { return a - Mod(1); }
Mod operator*(const Mod a, const Mod b) { return Mod(((long long)a.num * b.num) % mod); }
Mod operator*(const long long int a, const Mod b) { return Mod(a)*b; }
Mod operator*(const Mod a, const long long int b) { return Mod(b)*a; }
Mod operator*(const Mod a, const int b) { return Mod(b)*a; }
Mod operator+=(Mod &a, const Mod b) { return a = a + b; }
Mod operator+=(long long int &a, const Mod b) { return a = a + b; }
Mod operator-=(Mod &a, const Mod b) { return a = a - b; }
Mod operator-=(long long int &a, const Mod b) { return a = a - b; }
Mod operator*=(Mod &a, const Mod b) { return a = a * b; }
Mod operator*=(long long int &a, const Mod b) { return a = a * b; }
Mod operator*=(Mod& a, const long long int &b) { return a = a * b; }
Mod operator^(const Mod a, const int n) {
	if (n == 0) return Mod(1);
	Mod res = (a * a) ^ (n / 2);
	if (n % 2) res = res * a;
	return res;
}
Mod mod_pow(const Mod a, const long long  int n) {
	if (n == 0) return Mod(1);
	Mod res = mod_pow((a * a), (n / 2));
	if (n % 2) res = res * a;
	return res;
}

//mod が素数の場合のみ　違う場合はextend euclid を用いる。
Mod inv(const Mod a) { return a ^ (mod - 2); }
Mod operator/(const Mod a, const Mod b) {
	assert(b.num != 0);
	return a * inv(b);
}
Mod operator/(const long long int a, const Mod b) {
	return Mod(a) / b;
}
Mod operator/=(Mod &a, const Mod b) {
	return a = a / b;
}

#define MAX_MOD_N 1024000

Mod fact[MAX_MOD_N], factinv[MAX_MOD_N];
void init(const int amax = MAX_MOD_N) {
	fact[0] = Mod(1); factinv[0] = 1;
	for (int i = 0; i < amax - 1; ++i) {
		fact[i + 1] = fact[i] * Mod(i + 1);
		factinv[i + 1] = factinv[i] / Mod(i + 1);
	}
}
Mod comb(const int a, const int b) {
	return fact[a] * factinv[b] * factinv[a - b];
}
struct Edge {
	int src;
	int dst;
	int cost;
};
using Graph=vector<vector<Edge>>;


struct UnionFind {
	vector<int> data;
	UnionFind(int size) : data(size, -1) { }
	bool unionSet(int x, int y) {
		x = root(x); y = root(y);
		if (x != y) {
			if (data[y] < data[x]) swap(x, y);
			data[x] += data[y]; data[y] = x;
		}
		return x != y;
	}
	int root(int x) {
		return data[x] < 0 ? x : data[x] = root(data[x]);
	}
	int size(int x) {
		return -data[root(x)];
	}
};
int main() {
	/*int N,M,D,K;cin>>N>>M>>D>>K;
	vector<vector<int>>mat(N*10,vector<int>(N*10));
	Graph g(N);
	for (int i = 0; i < M; ++i) {
		int a,b;cin>>a>>b;a--;b--;
		int c;cin>>c;
		g[a].push_back(Edge{ a,b,c });
		g[b].push_back(Edge{ b,a,c });
	}

	for (int i = 0; i < N; ++i) {
		for (auto e : g[i]) {
			int src=e.src;
			int dst=e.dst;
			int cost=e.cost;
			mat[src*10][dst*10+cost-1]
		}
	}
	vector<Mod>start(10*N);
	for (int i = 0; i < N; ++i) {
		start[i*10]=Mod(1);
	}*/
	//int N,H,W;cin>>N>>H>>W;
	//int ans=(N-H+1)*(N-W+1);
	//cout<<ans<<endl;

	/*int N;cin>>N;
	int A,B;cin>>A>>B;
	vector<int>v(N);
	for(int i=0;i<N;++i)cin>>v[i];
	vector<int>nums(3);
	for (int i = 0; i < N; ++i) {
		if(v[i]<=A)nums[0]++;
		else if(v[i]<=B)nums[1]++;
		else nums[2]++;
	}
	cout<<*min_element(nums.begin(),nums.end())<<endl;*/

	int H,W;cin>>H>>W;
	vector<string>field(H);
	for(int i=0;i<H;++i)cin>>field[i];
	UnionFind uf(H*W);
	for (int i = 0; i < H; ++i) {
		for (int j = 0; j < W; ++j) {
			int dx[] = { -1,0,1,0 };
			int dy[] = { 0,1,0,-1 };
			for (int way = 0; way < 4; ++way) {
				int nextx=j+dx[way];
				int nexty=i+dy[way];
				if (nextx >= 0 && nextx < W&&nexty >= 0 && nexty < H) {
					if (field[i][j] != field[nexty][nextx]) {
						int aa=i*W+j;
						int bb=nexty*W+nextx;
						uf.unionSet(aa,bb);
					}
				}
			}
		}
	}
	map<int,pair<long long int,long long int>>mp;
	for (int i = 0; i < H; ++i) {
		for (int j = 0; j < W; ++j) {
			bool flag=(i+j)%2;
			if(flag)mp[uf.root(i*W+j)].first++;
			else mp[uf.root(i*W+j)].second++;
		}
	}
	long long int answer=0;
	for (auto m : mp) {
		answer+=m.second.first*m.second.second;
	}
	cout<<answer<<endl;
	return 0;
}

Measured memory_bytes: 17792