#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
  ll a,b,c,d,m;
  cin>>a>>b>>c>>d>>m;
  if(b+d-a-c>=m-1){
    cout<<m-1;
  }
  else if((a+c)/m==(b+d)/m){
    cout<<(b+d)%m;
  }
  else{
    cout<<m-1;
  }
}