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# include <bits/stdc++.h>
using namespace std ;
const int N = 44721 + 10 ; // 2e9=2000000000
//欧拉筛
int primes [ N ] , cnt ; // primes[]存储所有素数
bool st [ N ] ; // st[x]存储x是否被筛掉
void get_primes ( int n ) {
for ( int i = 2 ; i < = n ; i + + ) {
if ( ! st [ i ] ) primes [ cnt + + ] = i ;
for ( int j = 0 ; primes [ j ] < = n / i ; j + + ) {
st [ primes [ j ] * i ] = true ;
if ( i % primes [ j ] = = 0 ) break ;
}
}
}
int main ( ) {
// cout << sqrt(2e9) << endl;
int n ;
cin > > n ;
get_primes ( sqrt ( n ) ) ; //计算n的所有小质数因子范围 1~sqrt(n)
//枚举每个质数因子，
for ( int i = 0 ; i < cnt ; i + + ) {
if ( n % primes [ i ] = = 0 ) {
cout < < n / primes [ i ] < < endl ; //找出对应的大质数因子
break ;
}
}
return 0 ;
}
