import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Deque;
import java.util.HashMap;
import java.util.InputMismatchException;
import java.util.Map;
import java.util.PriorityQueue;
import java.math.BigInteger;
    
public class Main{

static final InputStream in=System.in;
static final PrintWriter out=new PrintWriter(System.out);
static final int INF=Integer.MAX_VALUE/2;
static final long LINF=Long.MAX_VALUE/2;
    
public static void main(String[] args) throws IOException{
InputReader ir=new InputReader(in);
int g=ir.nextInt();
int c=ir.nextInt();
int p=ir.nextInt();
int[][][] dp=new int[g+1][c+1][p+1];
char[] op=ir.next().toCharArray();
for(int i=g;i>=0;i--) for(int j=c;j>=0;j--) for(int k=p;k>=0;k--) dp[i][j][k]=Integer.MIN_VALUE;
dp[g][c][p]=0;
for(int i=g;i>=0;i--){
for(int j=c;j>=0;j--){
for(int k=p;k>=0;k--){
if(i!=g) dp[i][j][k]=Math.max(dp[i][j][k],dp[i+1][j][k]+getPoint('G',op[i+j+k]));
if(j!=c) dp[i][j][k]=Math.max(dp[i][j][k],dp[i][j+1][k]+getPoint('C',op[i+j+k]));
if(k!=p) dp[i][j][k]=Math.max(dp[i][j][k],dp[i][j][k+1]+getPoint('P',op[i+j+k]));
}
}
}
out.println(dp[0][0][0]);
out.flush();
}

public static int getPoint(char c1,char c2){
if(c1==c2) return 1;
else if((c1=='G'&&c2=='C')||(c1=='C'&&c2=='P')||(c1=='P'&&c2=='G')) return 3;
return 0;
}

static class InputReader {
private InputStream in;
private byte[] buffer=new byte[1024];
private int curbuf;
private int lenbuf;

public InputReader(InputStream in) {this.in=in;}
  
public int readByte() {
if(lenbuf==-1) throw new InputMismatchException();
if(curbuf>=lenbuf){
curbuf= 0;
try{
lenbuf=in.read(buffer);
}
catch (IOException e) {
throw new InputMismatchException();
}
if(lenbuf<=0)
return -1;
}
return buffer[curbuf++];
}

public boolean isSpaceChar(int c){return !(c>=33&&c<=126);}

private int skip() {int b; while((b = readByte())!=-1&&isSpaceChar(b)); return b;}

public String next() {
int b=skip();
StringBuilder sb=new StringBuilder();
while(!isSpaceChar(b)){
sb.appendCodePoint(b);
b=readByte();
}
return sb.toString();
}
 
public int nextInt() {
int c=readByte();
while (isSpaceChar(c)) c=readByte();
boolean minus=false;
if (c=='-') {
minus=true;
c=readByte();
}
int res=0;
do{
if(c<'0'||c>'9') throw new InputMismatchException();
res=res*10+c-'0';
c=readByte();
}while(!isSpaceChar(c));
return (minus)?-res:res;
}

public long nextLong() {
int c=readByte();
while (isSpaceChar(c)) c=readByte();
boolean minus=false;
if (c=='-') {
minus=true;
c=readByte();
}
long res = 0;
do{
if(c<'0'||c>'9') throw new InputMismatchException();
res=res*10+c-'0';
c=readByte();
}while(!isSpaceChar(c));
return (minus)?-res:res;
}

public int[] toIntArray(int n){
int[] a=new int[n];
for(int i=0;i<n;i++) a[i]=nextInt();
return a;
}
}
}