#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

#define dump(a) (cerr << (#a) << " = " << (a) << endl)

template<class T> inline void chmax(T& a, const T& b) { if(b > a) a = b; }
template<class T> inline void chmin(T& a, const T& b) { if(b < a) a = b; }

template<typename T, typename U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
	os << '(' << p.first << ", " << p.second << ')';
	return os;
}

template<class Tuple, unsigned Index>
void print_tuple(ostream& os, const Tuple& t) {}

template<class Tuple, unsigned Index, class Type, class... Types>
void print_tuple(ostream& os, const Tuple& t) {
	if(Index > 0) os << ", ";
	os << get<Index>(t);
	print_tuple<Tuple, Index + 1, Types...>(os, t);
}

template<class... Types>
ostream& operator<<(ostream& os, const tuple<Types...>& t) {
	os << '(';
	print_tuple<tuple<Types...>, 0, Types...>(os, t);
	return os << ')';
}

template<class Iterator>
ostream& dump_range(ostream&, Iterator, const Iterator&);

template<typename T>
ostream& operator<<(ostream& os, vector<T> c) {
	return dump_range(os, c.cbegin(), c.cend());
}

template<class Iterator>
ostream& dump_range(ostream& os, Iterator first, const Iterator& last) {
	os << '[';
	for(int i = 0; first != last; ++i, ++first) {
		if(i) os << ", ";
		os << *first;
	}
	return os << ']';
}

typedef complex<int> point;
#define X real()
#define Y imag()

bool operator<(const point& a, const point& b) {
	return a.X != b.X ? a.X < b.X : a.Y < b.Y;
}

inline int dist2(const point& a, const point& b) {
	const int diffX = a.X - b.X;
	const int diffY = a.Y - b.Y;
	return diffX * diffX + diffY * diffY;
}

inline double dist(const point& a, const point& b) {
	return sqrt(dist2(a, b));
}

int calc(const vector<string>& board, point start, point to) {
	point d = (to - start) / static_cast<int>(dist(to, start));
	int res = 0;
	point current = start;

	while(current != to) {
		if(board[current.Y][current.X] != '.') res |= (1 << (board[current.Y][current.X] - 'A'));
		current += d;
	}

	return res;
}

void update(queue<int>& que, vector<pair<int, int>>& can_erase, int value) {
	value = ~value;

	for(int i = 0; i < static_cast<int>(can_erase.size());) {
		can_erase[i].first &= value;
		if(can_erase[i].first == 0) {
			que.push(can_erase[i].second);
			can_erase.erase(can_erase.begin() + i);
		}
		else {
			++i;
		}
	}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int h, w;
	cin >> h >> w;

	vector<string> board(h);
	for(int i = 0; i < h; ++i) {
		cin >> board[i];
	}

	vector<vector<point>> tiles(26);
	for(int i = 0; i < h; ++i) {
		for(int j = 0; j < w; ++j) {
			if(board[i][j] != '.') {
				tiles[board[i][j] - 'A'].emplace_back(j, i);
			}
		}
	}

	vector<bool> used(26, true);
	vector<pair<int, int>> can_erase;

	for(int i = 0; i < 26; ++i) {
		if(tiles[i].size() == 0 || dist2(tiles[i][0], tiles[i][1]) == 1.0) continue;

		used[i] = false;
		if(tiles[i][1] < tiles[i][0]) swap(tiles[i][0], tiles[i][1]);

		if(tiles[i][0].X == tiles[i][1].X) {
			can_erase.emplace_back(calc(board, tiles[i][0] + point(0, 1), tiles[i][1]), i);
		}
		else if(tiles[i][0].Y == tiles[i][1].Y) {
			can_erase.emplace_back(calc(board, tiles[i][0] + point(1, 0), tiles[i][1]), i);
		}
		else {
			point start(tiles[i][0].X, tiles[i][1].Y);
			int obstacle = calc(board, start, tiles[i][0]);
			obstacle |= calc(board, start, tiles[i][1]);
			can_erase.emplace_back(obstacle, i);

			start = point(tiles[i][1].X, tiles[i][0].Y);
			obstacle = calc(board, start, tiles[i][0]);
			obstacle |= calc(board, start, tiles[i][1]);
			can_erase.emplace_back(obstacle, i);
		}
	}

	queue<int> que;
	update(que, can_erase, 0);

	int ans = 0;
	while(!que.empty()) {
		int color = que.front();
		que.pop();

		if(used[color]) continue;
		used[color] = true;
		++ans;

		update(que, can_erase, (1 << color));
	}

	cout << ans * 2 << endl;

	return EXIT_SUCCESS;
}

Measured memory_bytes: 1348