#include <iostream>
using namespace std;
int main(int argc, char* argv[])
{
	int A,B,S;
	cin>>A>>B>>S;

	int x1=A-S;
	if (x1<0){
		x1=-x1;
	}
	int ans;
	ans=x1+S;
	cout<<ans<<endl;
	return 0;
}