#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; } }