#include<iostream>
#include<fstream>
#include<algorithm>

using namespace std;

#define MAXN 100002

void input()
{
    freopen("building.in","r",stdin);
    freopen("building.out","w",stdout);
    cin.sync_with_stdio(0);
    cin.tie(0);
}

struct node
{
    int parent;
    int area;
    int weight;
    int strength;

    int weakest_parent;
};

int n;
node parts[MAXN];
int natovarenost[MAXN];

int main()
{
    input();
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>parts[i].parent>>parts[i].area>>parts[i].weight>>parts[i].strength;
        parts[i].weakest_parent = parts[i].parent;
        int p = parts[i].parent;
        if(p)
        {
            parts[p].area-=parts[i].area;
            if(parts[p].area<0)
            {
                cout<<"IMPOSSIBLE "<<i<<endl;
                return 0;
            }

            if(parts[p].weakest_parent)
            {
                // compare
                if ( parts[parts[p].weakest_parent].strength <= parts[p].strength )
                {
                    parts[i].weakest_parent = parts[p].weakest_parent;
                }
            }
        }

        if(parts[i].weakest_parent)
        {
            natovarenost[parts[i].weakest_parent]+=parts[i].weight;
            if(parts[parts[i].weakest_parent].strength < natovarenost[parts[i].weakest_parent])
            {
                cout<<"COLLAPSE "<<i<<endl;
                return 0;
            }
        }

    }
    return 0;
}