Largest Prime Divisor

#include<bits/stdc++.h>

using namespace std;

int main()
{

    long long n,i,cnt,LPD;

    while(scanf("%lld",&n)&&n)
    {
        if(n<0)
        {
            n*=-1;
        }

        cnt = 0;

        for(i=2;i*i<=n;i++)
        {
            if(n%i==0)
            {
                cnt++;

                while(n%i==0)
                {
                    n/=i;
                }

                LPD = i;
            }
        }

        if(n>1)
        {
            LPD = n;
            cnt++;
        }

        if(cnt>1)
        {
            printf("%lld\n",LPD);
        }
        else
        {
            printf("-1\n");
        }
    }
    return 0;
}