#include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>

using namespace std;
typedef long long ll;

int main(void) {
    int x, y, r;
    cin >> x >> y >> r;
    cout << (int)(abs(x) + abs(y) + 1.41421356*r) + 1 << endl;
    return 0;
}