#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000007
#define INF 1000000000 //(int)1e9
#define LLINF 2000000000000000000 //(ll)2e18
#define PI  3.1415926536

#define SIZE 100000

int dp[310][310][310];


int main(){
    int g,c,p,n;
    string s;
    
    cin >> g >> c >> p >> s;
    
    n = g+c+p;
    
    for(int i=0;i<310;i++){
        for(int j=0;j<310;j++){
            for(int k=0;k<310;k++){
                dp[i][j][k] = -INF;
            }
        }
    }
    
    dp[n][g][c] = 0;
    
    for(int i=n;i>0;i--){
        for(int j=0;j<=g;j++){
            for(int k=0;k<=c;k++){
                if(dp[i][j][k]==-INF) continue;
                
                if(s[n-i]=='G'){
                    if(j>0)      dp[i-1][j-1][k] = max(dp[i-1][j-1][k],dp[i][j][k]+1);
                    if(k>0)      dp[i-1][j][k-1] = max(dp[i-1][j][k-1],dp[i][j][k]+0);
                    if(i-j-k > 0)dp[i-1][j][k]   = max(dp[i-1][j][k]  ,dp[i][j][k]+3);
                }
                if(s[n-i]=='C'){
                    if(j>0)      dp[i-1][j-1][k] = max(dp[i-1][j-1][k],dp[i][j][k]+3);
                    if(k>0)      dp[i-1][j][k-1] = max(dp[i-1][j][k-1],dp[i][j][k]+1);
                    if(i-j-k > 0)dp[i-1][j][k]   = max(dp[i-1][j][k]  ,dp[i][j][k]+0);
                }
                if(s[n-i]=='P'){
                    if(j>0)      dp[i-1][j-1][k] = max(dp[i-1][j-1][k],dp[i][j][k]+0);
                    if(k>0)      dp[i-1][j][k-1] = max(dp[i-1][j][k-1],dp[i][j][k]+3);
                    if(i-j-k > 0)dp[i-1][j][k]   = max(dp[i-1][j][k]  ,dp[i][j][k]+1);
                }
            }
        }
    }
    
    cout << dp[0][0][0] << endl;
    
    return 0;
}