```
#include<iostream>
using namespace std;
int ta[21],tb[21];
int main()
{
int a,n,m,x;
cin>>a>>n>>m>>x;
ta[1]=1;ta[2]=1;ta[3]=2;
for(int i=4;i<n;i++)
{
ta[i]=ta[i-1]+ta[i-2]-1;
tb[i]=tb[i-1]+tb[i-2]+1;
}
int b=(m-a*ta[n-1])/tb[n-1];
cout<<ta[x]*a+tb[x]*b<<endl;
return 0;
}
by xxc123 @ 2023-04-10 21:55:37