Given the number n, find the smallest positive integer which has exactly n divisors. It is guaranteed that for the given n the answer will not exceed 1018.
Input
The first line of the input contains integer n (1 ≤ n ≤ 1000).
Output
Output the smallest positive integer with exactly n divisors.
Examples
Input
4
Output
6
Input
6
Output
12
反素数，这里先粘上以为大牛的博客，刚接触，也不敢在这里说什么。
https://blog.csdn.net/my_sunshine26/article/details/72772637
代码如下：
#include<bits/stdc++.h>
#define ll unsigned long long
using namespace std;
int prime[]={2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53};
ll ans;
int n;
void dfs(int pos,ll v,ll num)
{
if(num==n) ans=min(ans,v);
for(int i=1;i<=63;i++)
{
if(num*(i+1)>n||v*prime[pos]>ans) break;
dfs(pos+1,v*=prime[pos],num*(i+1));
}
}
int main()
{
ans=(ll)~0;;
scanf("%d",&n);
dfs(0,1,1);
printf("%llu\n",ans);
//cout<<ans<<endl;
}
努力加油a啊，(o)/~