#include <bits/stdc++.h>
#define int long long
using namespace std;
inline int read(){
    int x=0,f=1;char ch=getchar();
    for(;!isdigit(ch);ch=getchar()) if(ch=='-') f=-1;
    for(;isdigit(ch);ch=getchar()) x=x*10+ch-'0';
    return x*f;
}
signed main(){
	int n=read(),p=read(),q=read(),x=read(),y=read(),ans = 0;
	string s;
	cin>>s;
	int k = p;
	int len = s.length();
	for (int i=0;i<len;i++){
		if (s[i] == '-'){
			k--;
		}
		else if (s[i] == '+'){
			k++;
		}
	}
	if (k == q){
		cout<<0<<endl;
		return 0;
	}
	if (k>q){
		while (k!=q){
			ans+=x;
			k-=2;
		}
	}
	else {
		while (k!=q){
			ans+=x;
			k+=2;
		}
	}
	k = p;
	for (int i=0;i<len;i++){
		if (s[i] == '-'){
			k--;
		}
		else if (s[i] == '+'){
			k++;
		}
		if (k<0){
			k++;
			ans+=y;
			continue;
		}
	}
	cout<<ans<<endl;
	return 0;
}