[cf 599D] Spongebob and Squares

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <vector>

using namespace std;

vector<pair<long long,long long> >S;

int main()
{
    long long    x,i,Ans=0;

    scanf("%lld",&x);
    for(i=1;;++i)
    {
        long long n=i,m=(6LL*x-n+n*n*n)/(3*n*n+3*n);
        if(n>m)break;
        if((6LL*x-n+n*n*n)%(3*n*n+3*n)==0)
        {
            S.push_back(make_pair(n,m));
        }
    }
    if(S.back().first==S.back().second)
    {
        Ans=-1;
    }
    Ans+=(int)S.size()<<1;

    printf("%lld\n",Ans);
    for(i=0;i<(int)S.size();++i)
    {
        printf("%lld %lld\n",S[i].first,S[i].second);
    }

    if(S.back().first==S.back().second)
    {
        S.pop_back();
    }
    

    while(!S.empty())
    {
        printf("%lld %lld\n",S.back().second,S.back().first);
        S.pop_back();
    }
    return 0;
}