#include <iostream>
#include <string>
#include <algorithm>
#include<bits/stdc++.h>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <map>
#define rep(i,N) for (ll i = 0; i < (N); i++)
#define REP(i,N) for (ll i = (N)-1; i >= 0; i--)
#define FOR(j,i,N) for (ll j = (N)-1; j > (i); j--)
#define ST string
#define vec vector<ll>
#define out(s) cout << s << endl;
#define Graph vector<vector<ll>>
#define vecs vector<ST>
#define vecb vector<lb>
using ll = long long;
using lb = long double;
using namespace std;
const ll mod = 1000000007;
const ll ze = 0;
const lb pi = 3.14159265358979;
 
ll nCk(ll N, ll K){
  if(N>1){
    ll kid = 1;
  for(ll i = N; i > N - K; i--){
      kid = kid * i;
    }
    for(ll i = 1; i < K + 1; i++){
        kid = kid / i;
    }
  return kid;
  }
  else{
    return 0;
  }
}
 
ll stair_pow(ll N){// 階乗
  ll sum = 1;
  for(ll i = 1; i <= N; i++){
    sum = sum * i % mod;
  }
  return sum % mod;
}
 
ll gcd(ll P, ll Q){
  return Q ? gcd(Q,P % Q):P;
}
 
ll lcm(ll P, ll Q){
  return P / gcd(P,Q) * Q;
}
 
string change_big(string str){
  transform(str.begin(), str.end(), str.begin(), ::toupper);
  return str;
}
 
string change_small(string str){
  transform(str.begin(), str.end(), str.begin(), ::tolower);
  return str;
}
 
bool is_prime(ll x){
  if(x <= 1){
    return false;
  }
  for(ll i=2; i * i <= x; i++){
    if(x%i==0){ 
      return false;
    }
  }
  return true;
}
 
ll sum_of_num(ll num){// 各位の和
  ll dig;
  ll sum = 0;
  while(num){
    dig = num % 10;
    sum = sum + dig;
    num = num / 10;
  }
  return sum;
}
 
ll how_many_break(ll n, ll m){// 何回割れるか
  ll counter = 0;
  while (n % m == 0){
    n = n / m;
    counter++;
  }
  return counter;
}
 
ll many_pow(ll N, ll M){ // NのM乗
  if(M == 0)return 1;
  else{
    ll sum = 1;
    for(ll i = 0; i < M; i++){
      sum *= N;
    }
    return sum;
  }
}
 
ll one_to_i(ll i){ // 1からiまでの和
  if(i < 0){
    return 0;
  }
  else{
    return i*(i+1)/2;
  }
}
 
ll how_many_yaku(ll num){
  ll ans = 0;
   rep(i,num){
    if(num % (i+1) == 0)ans++;
  }
  return ans;
}
 
ll Digit(ll num){
    ll digit=0;
    while(num!=0){
        num /= 10;
        digit++;
    }
    return digit;
}

ll binary_search(ll left, ll right, ll N){
  ll count = 0;
  while (right - left > 1) {
    ll mid = left + (right - left) / 2; 
    if (mid <= N) left = mid;
    else right = mid;
    count++;
  }
  return count;
}
 
/*-----------------------------------------------------------------------------------*/
 
// cout << fixed << setprecision(15)
 
/*
  vector<pair<int, int>> p(N);
  for (int i = 0; i < N; i++) {
    int A, B;
    cin >> A >> B;
    p.at(i) = make_pair(A, B); 
  }
  sort(p.begin(), p.end()); */
 
/*
    ll B,A;
    tie(A,B) = p.at(i); */
 
// continue
 
// count(S.begin(),S.end(),'');
 
//reverse(S.begin(), S.end());
 
/*   ll N;
  cin >> N;
  vec P(N);
  rep(i,N)cin >> P[i];
  map<int, int> Q;
  for(ll i : P){
    if(Q.count(i)){
      Q.at(i)++;
    }
    else{
      Q[i]++;
    }
  }*/
 
// S.substr(8, 8)
 
/*-----------------------------------------------------------------------------------*/

int main(){
  ll N,M;
  cin >> N >> M;
  ll m = 0;
  m = min(N,M);
  N = max(N,M);
  M = m;
  cout << min(N-1,M)*2 << endl;
  return 0;
}