#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll n,x,y;
string a,b;
int main() {
    freopen("zerone.in","r",stdin);
    freopen("zerone.out","w",stdout);
    cin>>n>>x>>y;
    cin>>a>>b;
    if(a==b)
    {
		cout<<0<<endl;
        return 0;
	}
	vector<int> d;
    for(int i=0;i<n;i++)
        if(a[i]!=b[i])
            d.push_back(i);
    n=d.size();
    if(n&1==1)
    {
    	cout<<-1<<endl;
        return 0;
	}
    if(n==2&&d[1]-d[0]==1)
    {
		cout<<min(x,2*y)<<endl;
        return 0;
	}
    if(y<x)
	{
		cout<<n/2*y<<endl;
        return 0;
	}
	vector<ll> f(n);
    f[0]=y,f[1]=min(f[0]+y,2*x*(d[1]-d[0]));
    for(int i=2;i<n;++i) 
        f[i]=min(f[i-1]+y,f[i-2]+2*x*(d[i]-d[i-1]));
    cout<<f[n-1]/2<<endl;
    return 0;
}