#include <iostream>

int main(void){
  using namespace std;
  long l,r,m;
  cin >> l >> r >> m;
  if(0<m && m<l) cout << m << endl;
  if(0<l && l<m && m<r) cout << r-l+1 << endl;
  if(r<m) cout << r-l+1 << endl;
  if(m==1) cout << m << endl;
  return 0;    
}