#include<vector>
#include<map>
#include<climits>
#include<set>
#include<queue>
#include<algorithm>
#include<functional>
#include<numeric>
#include<utility>
#include<sstream>
#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cctype>
#include<string>
#include<bitset>
#include<cstring>
#include<list>
#include<iterator>
using namespace std;
typedef vector<string>vs;
typedef vector<int>vi;
typedef vector<vi>vvi;
typedef pair<int,int>pii;
typedef long long ll;
typedef pair<ll,ll>pll;
#define rrep(i,x,n) for(int i=(x);i<(n);++i)
#define rep(i,x) rrep(i,0,(x))
#define fi first
#define se second
#define each(i,c) for(typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define all(c) (c).begin(),(c).end()
#define rall(c) (c).rbegin(),(c).rend()
#define pb push_back
#define maxs(a,b) (a)=max(a,b)
struct data{
    int g,c,p;
    data(int x,int y,int z):
        g(x),c(y),p(z){}
    data(){}
    bool operator<(const data &d)const{
        if(g!=d.g)return g<d.g;
        if(c!=d.c)return c<d.c;
        return p<d.p;
    }
};
int main(){
    int G,C,P;string str;
    cin>>G>>C>>P>>str;

    map<data,int>prev;
    prev[data(G,C,P)]=0;

    rep(i,str.size()){
        map<data,int>next;
        each(it,prev){
            data d=it->first;
            if(d.g>0){
                int p;
                if(str[i]=='C')p=3;
                else if(str[i]=='G')p=1;
                else p=0;
                maxs(next[data(d.g-1,d.c,d.p)],it->second+p);
            }

            if(d.c>0){
                int p;
                if(str[i]=='P')p=3;
                else if(str[i]=='C')p=1;
                else p=0;
                maxs(next[data(d.g,d.c-1,d.p)],it->second+p);
            }
            if(d.p>0){
                int p;
                if(str[i]=='G')p=3;
                else if(str[i]=='P')p=1;
                else p=0;
                maxs(next[data(d.g,d.c,d.p-1)],it->second+p);
            }
        }
        prev=next;
    }
    int ma=0;
    each(it,prev)ma=max(ma,it->second);

    cout<<ma<<endl;
}