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