#include <bits/stdc++.h>
using namespace std;


#define ll long long int
#define vecint vector<int>
#define vecchar vector<char>
#define max_ele(v) *max_element(v.begin(), v.end())
#define min_ele(v) *min_element(v.begin(), v.end())
#define sort(v) sort(v.begin(), v.end())
#define rev_sort(v) sort((v).begin(), (v).end(), greater<>())
#define Reverse(v) reverse(v.begin(), v.end())
#define pb push_back
#define ppb pop_back()
#define pf push_front
#define coutall(v) for(auto &it: v) cout<<it<<" "
#define coutnewline(v) for(auto &it: v) cout<<it<<'\n'
#define cinall(v) for(auto &it: v) cin>>it
#define yes cout<<"YES\n"
#define no cout<<"NO\n"

void solve()
{
    int x;
    cin >> x;
    if(2*x<=100) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
}

int main()
{
    // int tests;
    // cin >> tests;
    // while (tests-- > 0)
    // {
    // }
        solve();
    
    return 0;
}