//#include <bits/stdc++.h>

#include <iostream>
#include <algorithm>

#include <bitset>
#include <vector>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <stack>
#include <queue>
#include <deque>
#include <cstring>
#include <string>
#include <utility>
#include <array>
#include <complex>
#include <valarray>

#include <cassert>
#include <cmath>
#include <functional>
#include <iomanip>
#include <chrono>
#include <random>
#include <numeric>

#include<memory>


using namespace std;
#define int long long

typedef long long ll;
typedef unsigned long long ull;
//typedef unsigned __int128 HASH;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll,int> plli;
typedef pair<double,int> pdi;
typedef pair<long double, int> pdbi;
typedef pair<int,pii> pipii;
typedef pair<ll,pll> plpll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pii> vpii;
typedef vector<vector<int>> mat;

#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n);i>0;i--)
#define rrep2(i,a,b) for (int i=(a);i>b;i--)
#define pb push_back
#define fi first
#define se second
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()

const ll hmod1 = 999999937;
const ll hmod2 = 1000000000 + 9;
const int INF = 1<<30;
const ll INFLL = 1LL<<62;
const long double EPS = 1e-12;
const ll mod = 1000000000 + 7;
//const ll mod = 998244353;
const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, 1, 0, -1};
const int dx8[8] = {1, 1, 1, 0, 0, -1, -1, -1};
const int dy8[8] = {0, 1, -1, 1, -1, 0, 1, -1};
const long double pi = 3.141592653589793;

#define addm(X, Y) (X) = ((X) + ((Y) % mod) + mod) % mod
#define inside(y, x, h, w) (0 <= (y) && (y) < (h) && 0 <= (x) && (x) < (w)) ? true : false

//debug
#define DEBUG

#define DUMPOUT cerr

#ifdef DEBUG
#define dump(...) DUMPOUT<<#__VA_ARGS__<<" :["<<__FUNCTION__<<":"<<__LINE__<<"]"<<endl; DUMPOUT<<"    "; dump_func(__VA_ARGS__)
#else
#define dump(...)
#endif

void dump_func() {DUMPOUT << endl;};

template <class Head, class... Tail> void dump_func(Head&& head, Tail&&... tail) {
    DUMPOUT << head;
    if (sizeof...(Tail) == 0) DUMPOUT << " ";
    else DUMPOUT << ", ";
    dump_func(std::move(tail)...);
}

//ostream
template<typename T> ostream& operator << (ostream& os, vector<T>& vec) {
    os << "["; for (int i = 0; i<vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : ", "); os << "]";
    return os;
}

template<typename T, typename U> ostream& operator << (ostream& os, pair<T, U>& pair_var) {
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}

template<typename T, typename U> ostream& operator << (ostream& os, map<T, U>& map_var) {
    os << "[";
    for (auto itr = map_var.begin(); itr != map_var.end(); itr++) {
        os << "(" << itr->first << ", " << itr->second << ")"; itr++;  if(itr != map_var.end()) os << ", "; itr--;
    }
    os << "]";
    return os;
}

template<typename T> ostream& operator << (ostream& os, set<T>& set_var) {
    os << "[";
    for (auto itr = set_var.begin(); itr != set_var.end(); itr++) {
        os << *itr; ++itr; if(itr != set_var.end()) os << ", "; itr--;
    }
    os << "]";
    return os;
}

int m, n;
char C[501][501];
map<char, vector<pii>> pos;
vector<vector<pii>> kouho(26);

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> m >> n;
  rep(i, m)rep(j, n) {
    cin >> C[i][j];
    if (C[i][j] != '.') {
      pos[C[i][j]].push_back({i, j});
    }
  }
  for (auto p : pos) {
    char c = p.fi;
    vector<pii> yx = p.se;
    int Y1 = yx[0].fi;
    int X1 = yx[0].se;
    int Y2 = yx[1].fi;
    int X2 = yx[1].se;
    if (Y1 == Y2) {
       for (int x = min(X1, X2)+1; x < max(X1, X2); x++) {
         kouho[c - 'A'].push_back({Y1, x});
       }
    }
    else if (X1 == X2) {
       for (int y = min(Y1, Y2)+1; y < max(Y1, Y2); y++) {
         kouho[c - 'A'].push_back({y, X1});
       }
    }
    else {
      kouho[c - 'A'].push_back({min(Y1, Y2), min(X1, X2)});
      kouho[c - 'A'].push_back({max(Y1, Y2), max(X1, X2)});
      kouho[c - 'A'].push_back({min(Y1, Y2), max(X1, X2)});
      kouho[c - 'A'].push_back({max(Y1, Y2), min(X1, X2)});
    }
  }
  int ans = 0;
  bool check[26] = {};
  while (true) {
    bool update = false;
    rep(i, 26) {
      if (check[i]) continue;
      for (auto p : kouho[i]) {
        int y = p.fi;
        int x = p.se;
        if (C[y][x] != '.') continue;
        int cnt[26] = {};
        rep2(j, y, m) {
          if (C[j][x] != '.') {
            cnt[C[j][x] - 'A']++;
            break;
          }
        }
        rrep2(j, y, -1) {
          if (C[j][x] != '.') {
            cnt[C[j][x] - 'A']++;
            break;
          }
        }
        rep2(j, x, n) {
          if (C[y][j] != '.') {
            cnt[C[y][j] - 'A']++;
            break;
          }
        }
        rrep2(j, x, -1) {
          if (C[y][j] != '.') {
            cnt[C[y][j] - 'A']++;
            break;
          }
        }
        rep(j, 26) {
          if (cnt[j] == 2) {
            //cerr << char(j + 'A') << endl;
            update = true;
            ans += 2;
            check[j] = true;
            vector<pii> tmppos = pos[char(j + 'A')];
            for (auto p : tmppos) {
              C[p.fi][p.se] = '.';
            }
            /*
            rep(i, m) {
              rep(j, n) cerr << C[i][j];
              cerr << endl;
            }
            */
          }
        }
      }
    }
    if (!update) break;
  }
  cout << ans << endl;
}



Measured memory_bytes: 3552