#include<bits/stdc++.h> using namespace std; int a[100010],b[100010],ans,k,x,y,p,q; int main(){ cin>>k>>x>>y>>p>>q; for(int i=1;i<=k;i++)if((i%(x+y)>x||i%(x+y)==0)&&(i%(p+q)>p||i%(p+q)==0))ans++; cout<<ans; return 0; }