#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

const int S = 1747;

int f[2][2 * S][2 * S];

void add(int i, int x, int y, int d)
{
	f[i][x + S][y + S] += d;
}

int get(int i, int x, int y)
{
	if (x < 0 || x >= 2 * S || y < 0 || y >= 2 * S)
		return 0;
	return f[i][x][y];
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout << fixed << setprecision(2);
	int n;
	cin >> n;
	FOR(i, 0, n)
	{
		char c;
		int x, y, a;
		cin >> c >> x >> y >> a;
		a /= 2;
		if (c == 'A')
		{
			for (int sx : {-1, 1})
				for (int sy : {-1, 1})
					add(0, x + sx * a, y + sy * a, sx * sy);
		}
		else
		{
			add(1, x - a, y, 1);
			add(1, x, y - a, -1);
			add(1, x, y + a, -1);
			add(1, x + a, y, 1);
		}
	}
	FOR(x, 0, 2 * S)
		FOR(y, 1, 2 * S)
			f[0][x][y] += f[0][x][y - 1];
	FOR(x, 1, 2 * S)
		FOR(y, 0, 2 * S)
			f[0][x][y] += f[0][x - 1][y];
	FOR(x, 1, 2 * S)
		RFOR(y, 2 * S - 1, 0)
			f[1][x][y] += f[1][x - 1][y + 1];
	FOR(x, 1, 2 * S)
		FOR(y, 1, 2 * S)
			f[1][x][y] += f[1][x - 1][y - 1];
	int ans = 0;
	FOR(x, 0, 2 * S)
		FOR(y, 0, 2 * S)
		{
			if (f[0][x][y] > 0)
			{
				ans += 4;
				continue;
			}
			// lower
			if (get(1, x, y) > 0 || get(1, x - 1, y - 1) > 0)
				ans++;
			//left
			if (get(1, x - 1, y) > 0 || get(1, x - 1, y + 1) > 0)
				ans++;
			//upper
			if (get(1, x, y + 1) > 0 || get(1, x - 1, y + 1) > 0)
				ans++;
			//right
			if (get(1, x, y) > 0 || get(1, x, y + 1) > 0)
				ans++;
		}
	cout << ans / 4.0 << "\n";
	return 0;
}