#include <iostream>
#include <vector>
#include <string>
#include <utility>
#include <algorithm>
#include <climits>
#include <map>
#include <queue>
#include <cmath>

using namespace std;

using int64 = long long;

int main() {
    int x,y,r;
    cin >> x >> y >> r;

    int ans = ceil(abs(x) + abs(y) + sqrt(2)*r);
    cout << ans << endl;
}