#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main(){
	int G, C, P;
	cin >> G >> C >> P;
	string S;
	cin >> S;
	vector<vector<vector<int>>> dp(G + 1, vector<vector<int>>(C + 1, vector<int>(P + 1, 0)));
	for (int i = 0; i <= G; i++){
		for (int j = 0; j <= C; j++){
			for (int k = 0; k <= P; k++){
				if (!(i == G && j == C && k == P)){
					if (S[i + j + k] == 'G'){
						if (i < G){
							dp[i + 1][j][k] = max(dp[i + 1][j][k], dp[i][j][k] + 1);
						}
						if (j < C){
							dp[i][j + 1][k] = max(dp[i ][j + 1][k], dp[i][j][k]);
						}
						if (k < P){
							dp[i][j][k + 1] = max(dp[i][j][k + 1], dp[i][j][k] + 3);
						}
					}
					if (S[i + j + k] == 'C'){
						if (i < G){
							dp[i + 1][j][k] = max(dp[i + 1][j][k], dp[i][j][k] + 3);
						}
						if (j < C){
							dp[i][j + 1][k] = max(dp[i][j + 1][k], dp[i][j][k] + 1);
						}
						if (k < P){
							dp[i][j][k + 1] = max(dp[i][j][k + 1], dp[i][j][k]);
						}
					}
					if (S[i + j + k] == 'P'){
						if (i < G){
							dp[i + 1][j][k] = max(dp[i + 1][j][k], dp[i][j][k]);
						}
						if (j < C){
							dp[i][j + 1][k] = max(dp[i][j + 1][k], dp[i][j][k] + 3);
						}
						if (k < P){
							dp[i][j][k + 1] = max(dp[i][j][k + 1], dp[i][j][k] + 1);
						}
					}
				}
			}
		}
	}
	cout << dp[G][C][P] << endl;
}