#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using pii = pair <int, int>;
const ll mod = 998244353;
//~ const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
	for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }

int main() {
	ios :: sync_with_stdio(false);
	
	int x, y, r; cin >> x >> y >> r;
	
	int a = max({x + y, x - y, -x + y, -x - y});
	
	cout << int(ceil(a + sqrt(2) * r)) << '\n';
}