#include <stdio.h>
int main(){
   int a,b,c,ans;
   scanf("%d %d %d",&a,&b,&c);
   if(a < c){
      ans = b-c;
      if(ans > c-a)ans = c-a;
   }else {
      ans = b-a;
      if(ans > a-c)ans = a-c;
   }
   if(ans < 0)ans = 0;
   printf("%d\n",ans);
}