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

#define ll long long

ll eular(ll n)
{
    ll ans=n;
    for(int i=2;i*i<=n;i++)
    {
        if(n%i==0)
        {
            ans-=ans/i;
            while(n%i==0)
            {
                n/=i;
            }
        }
    }
    if(n>1) ans-=ans/n;
    return ans;
}