#include<bits/stdc++.h>
using namespace std;
#define ll long long
typedef pair<ll,ll> P;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
#define M 1000000007
#define all(a) (a).begin(),(a).end()
#define rep(i,n) reps(i,0,n)
#define reps(i,m,n) for(int i=(m);i<(n);i++)
int main(){
  int a,b,c;cin>>a>>b>>c;
  cout<<min(b-max(a,c)+1,max(a,c)-min(a,c));
  cout<<endl;
}