#include <bits/stdc++.h>

 using namespace std;

 typedef long long ll;

 int main()

 {

     ll a[], e;

     ll sum = ;

     for (int i = ; i <= ; i++)

     {

         scanf("%lld ", &a[i]);

     }

     scanf("%lld", &e);

     if (a[] < a[] || a[] < a[])

     {

         cout << ;

         return ;

     }

     else

     {

         sort(a + , a + );

         sum = a[] - a[] + ;

         if (e >= a[] && e <= a[])

         {

             sum--;

         }

         cout << sum << endl;

     }

     return ;

 }