#include <bits/stdc++.h>
#define VuDucNam ios_base::sync_with_stdio(false);
#define Lop9a6 cin.tie(NULL);
#define THCSPhamVanDong cout.tie(NULL);
#define ll long long
#define el cout << '\n'
#define sz(a) (ll) a.size()
#define all(a) a.begin(), a.end()
#define fi first
#define se second
#define fill(a, x) memset(a, x, sizeof(a))
#define file(name) \
if (fopen(name ".inp", "r")) \
freopen(name ".inp", "r", stdin); \
freopen(name ".out", "w", stdout);
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define RUNTIME cerr << "\nRuntime: " << TIME << "s.\n"
using namespace std;
const ll MOD = 1e9 + 7;
const ll inf = LLONG_MAX;
int n;
ll ans=1;
void solve()
{
cin >> n;
for(int i=2;i<=sqrt(n);++i){
if(n%i==0){
if(i%2==0) ans*=i;
if(i!=n/i && n/i%2==0)
ans*=(n/i);
}
}
if(ans==1){
if(n%2==0)
cout << n;
else cout << "0";
}else cout << ans;
el;
}
int main()
{
VuDucNam Lop9a6 THCSPhamVanDong
// file();
solve();
return 0;
}
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