#include <bits/stdc++.h>
#define rep(i,n) for(int i=(0);i<(n);i++)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

string s;

int sco(char c, int i){
	char x = s[i];
	if(c == 'G'){
		if(x == 'G') return 1;
		if(x == 'C') return 3;
		return 0;
	}

	if(c == 'C'){
		if(x == 'G') return 0;
		if(x == 'C') return 1;
		return 3;
	}

	// p
	if(x == 'G') return 3;
	if(x == 'C') return 0;
	return 1;

}

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

	int g, c, p;
	cin >> g >> c >> p;

	cin >> s;
	int n = s.size();

	vector<int> ps(n, -1);

	// win
	rep(i, n){
		if(ps[i] > -1) continue;
		if(s[i] == 'G' && p > 0){
			ps[i] = 3;
			p--;
		}

		if(s[i] == 'C' && g > 0){
			ps[i] = 3;
			g--;
		}

		if(s[i] == 'P' && c > 0){
			ps[i] = 3;
			c--;
		}
	}

	// draw
	rep(i, n){
		if(ps[i] > -1) continue;
		if(s[i] == 'G' && g > 0){
			ps[i] = 1;
			g--;
		}

		if(s[i] == 'C' && c > 0){
			ps[i] = 1;
			c--;
		}

		if(s[i] == 'P' && p > 0){
			ps[i] = 1;
			p--;
		}
	}

	// lose
	rep(i, n){
		if(ps[i] > -1) continue;
		ps[i] = 0;
	}

	int ans = 0;
	rep(i, n) ans += ps[i];
	cout << ans << endl;
}