#include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>

using namespace std;
typedef long long ll;

int dp[2][334][334][334];

int main(void) {
    int G, C, P;
    cin >> G >> C >> P;
    string s;
    cin >> s;
    int n = s.size();
    for (int i = 0; i < n; i++) {
        int p = i%2;
        for (int j = 0; j <= G; j++) {
            for (int k = 0; k <= C; k++) {
                for (int l = 0; l <= P; l++) {
                    if (s[i] == 'G') {
                        if (j > 0) dp[p][j-1][k][l] = max(dp[p][j-1][k][l], dp[1-p][j][k][l]+1);
                        if (k > 0) dp[p][j][k-1][l] = max(dp[p][j][k-1][l], dp[1-p][j][k][l]);
                        if (l > 0) dp[p][j][k][l-1] = max(dp[p][j][k][l-1], dp[1-p][j][k][l]+3);
                    }
                    if (s[i] == 'C') {
                        if (j > 0) dp[p][j-1][k][l] = max(dp[p][j-1][k][l], dp[1-p][j][k][l]+3);
                        if (k > 0) dp[p][j][k-1][l] = max(dp[p][j][k-1][l], dp[1-p][j][k][l]+1);
                        if (l > 0) dp[p][j][k][l-1] = max(dp[p][j][k][l-1], dp[1-p][j][k][l]);
                    }
                    if (s[i] == 'P') {
                        if (j > 0) dp[p][j-1][k][l] = max(dp[p][j-1][k][l], dp[1-p][j][k][l]);
                        if (k > 0) dp[p][j][k-1][l] = max(dp[p][j][k-1][l], dp[1-p][j][k][l]+3);
                        if (l > 0) dp[p][j][k][l-1] = max(dp[p][j][k][l-1], dp[1-p][j][k][l]+1);
                    }
                }
            }
        }
    }
    cout << max(dp[0][0][0][0], dp[1][0][0][0]) << endl;
    return 0;
}