#include <bits/stdc++.h>

#define REP(i, x, n) for(int i = x; i < (int)(n); i++)
#define rep(i, n) REP(i, 0, n)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define F first
#define S second
#define mp make_pair

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
// typedef pair<int, int> P;

vector<vector<vector<int>>> dp;
int G, C, P;
string S;

int rec(int idx, int g, int c, int p) {
  if(g == 0 && c == 0 && p == 0) return 0;

  if(dp[g][c][p] != -1) return dp[g][c][p];

  int res = 0;
  if(g - 1 >= 0) {
    int tmp = 0;
    if(S[idx] == 'C') tmp = 3;
    if(S[idx] == 'G') tmp = 1;
    res = max(res, rec(idx + 1, g - 1, c, p) + tmp);
  }
  if(c - 1 >= 0) {
    int tmp = 0;
    if(S[idx] == 'P') tmp = 3;
    if(S[idx] == 'C') tmp = 1;
    res = max(res, rec(idx + 1, g, c - 1, p) + tmp);
  }
  if(p - 1 >= 0) {
    int tmp = 0;
    if(S[idx] == 'G') tmp = 3;
    if(S[idx] == 'P') tmp = 1;
    res = max(res, rec(idx + 1, g, c, p - 1) + tmp);
  }

  return dp[g][c][p] = res;
}

int main() {
  cin >> G >> C >> P;
  cin >> S;
  dp = vector<vector<vector<int>>>(G + 1, vector<vector<int>>(C + 1, vector<int>(P + 1, -1)));
  cout << rec(0, G, C, P) << endl;
  return 0;
}