#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long k = min(a, b);
  a -= k;
  b -= k;
  c += k;
  if (a > 0 || b > 0)
    cout << c * 2 + 1;
  else
    cout << c * 2;
}
