#include<iostream>
using namespace std;
int main(){
	int a,b,c,d;
	int aa[3];
	cin>>a>>b>>c;
	d=aa[3]+aa[3]-aa[2];
	if(a<b&&a<c){
		aa[1]==a;
		if(b<c){
			aa[2]==b;
			aa[3]==c;
		}
		else{
			aa[2]==c;
			aa[3]==c;
		}
	}
	else if(a<c&&a>b){
		aa[1]==b;
		aa[2]==a;
		aa[3]==c;
	}
	else if(a<b&&a>c){
		aa[1]==c;
		aa[2]==a;
		aa[3]==b;
	}
	else if(a>b&&a>c&&b>c){
		aa[1]==c;
		aa[2]==b;
		aa[3]==a;
	}
	else if(a>c&&a>b&&c>b){
		aa[1]==b;
		aa[2]==c;
		aa[3]==a;
	}
	cout<<d;
	return 0;
}