#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define pb(a) push_back(a)
#define pr(a) cout<<(a)<<endl
#define PR(a,b) cout<<(a)<<" "<<(b)<<endl
#define R cin>>
#define F first
#define S second
#define ll long long
bool check(int n,int m,int x,int y){return (x<0||x>=n||y<0||y>=m)?false:true;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<int,int> P;

int main() {
  int g,c,p;
  string s;
  cin >> g >> c >> p >> s;
  bool u[s.size()];
  memset(u,0,sizeof(u));
  int ans=0;
  rep(i,s.size()) {
    if(s[i]=='C' && g) {
      g--;ans+=3;u[i]=1;
    }
    if(s[i]=='P' && c) {
      c--;ans+=3;u[i]=1;
    }
    if(s[i]=='G' && p) {
      p--;ans+=3;u[i]=1;
    }
  }
  rep(i,s.size()) {
    if(u[i]) continue;
    if(s[i]=='C' && c) {
      c--;ans+=1;
    }
    if(s[i]=='P' && p) {
      p--;ans+=1;
    }
    if(s[i]=='G' && g) {
      g--;ans+=1;
    }
  }
  cout << ans << endl;
  return 0;
}