hdu 5108 Alexandra and Prime Numbers

#include <cstdio>
#include <cstring>
#include <algorithm>
#define ll long long
#define N 100000
using namespace std;

ll n;

int main()
{
while(scanf("%lld",&n)!=EOF)
{
ll m=n;
if(n==1)
{
printf("0\n");
continue;
}
bool flag=false;
for(int i=2; i*i<=n; i++)
{
if(n%i==0)
{
flag=true;
break;
}
}
if(!flag)
{
printf("1\n");
continue;
}
ll max1=2;
for(int i=2; i*i<=n; i++)
{
if(n%i==0)
{
if(max1<i) max1=i;
while(n%i==0) n/=i;
}
}
if(n>1)
{
if(max1<n)
{
max1=n;
}
}
printf("%lld\n",m/max1);
}
return 0;
}