#include <bits/stdc++.h>
//#include<boost/multiprecision/cpp_int.hpp>
//#include<boost/multiprecision/cpp_dec_float.hpp>
//#include <atcoder/all>
#define rep(i, a) for (int i = (int)0; i < (int)a; ++i)
#define rrep(i, a) for (int i = (int)a - 1; i >= 0; --i)
#define REP(i, a, b) for (int i = (int)a; i < (int)b; ++i)
#define RREP(i, a, b) for (int i = (int)a - 1; i >= b; --i)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define popcount __builtin_popcount
#define fi first
#define se second
using ll = long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 60;

// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")

//using lll=boost::multiprecision::cpp_int;
//using Double=boost::multiprecision::number<boost::multiprecision::cpp_dec_float<1024>>;//仮数部が1024桁
template <class T>
inline bool chmin(T &a, T b)
{
	if (a > b)
	{
		a = b;
		return true;
	}
	return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
	if (a < b)
	{
		a = b;
		return true;
	}
	return false;
}

template <typename T>
T mypow(T x, T n, const T &p = -1)
{ //x^nをmodで割った余り

	if(p!=-1){
		x%=p;
	}
	T ret = 1;
	while (n > 0)
	{
		if (n & 1)
		{
			if (p != -1)
				ret = (ret * x) % p;
			else
				ret *= x;
		}
		if (p != -1)
			x = (x * x) % p;
		else
			x *= x;
		n >>= 1;
	}
	return ret;
}

using namespace std;
//using namespace atcoder;

int dp[2][301][301][301];
void solve()
{	
	int g,c,p;
	cin>>g>>c>>p;
	string s;
	cin>>s;
	int n=s.size();

	auto judge=[](char a,char b)->int{
		if(a==b)return 1;
		if(a=='G'){
			if(b=='C')return 3;
			else return 0;
		}
		else if(a=='C'){
			if(b=='P')return 3;
			else return 0;
		}
		else{
			if(b=='G')return 3;
			else return 0;
		}
	};
	
	memset(dp,-1,sizeof(dp));
	dp[0][g][c][p]=0;
	rep(i,n){
		rep(x,g+1){
			rep(y,c+1){
				rep(z,p+1){
					int pre=i%2,id=(i+1)%2;
					if(dp[i%2][x][y][z]==-1)continue;
					if(x-1>=0)chmax(dp[id][x-1][y][z],dp[pre][x][y][z]+judge('G',s[i]));
					if(y-1>=0)chmax(dp[id][x][y-1][z],dp[pre][x][y][z]+judge('C',s[i]));
					if(z-1>=0)chmax(dp[id][x][y][z-1],dp[pre][x][y][z]+judge('P',s[i]));
					dp[pre][x][y][z]=-1;
				}
			}
		}
	}
	cout<<dp[n%2][0][0][0]<<"\n";
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}