#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vvi vector<vi>
#define vll vector<ll>
#define vvll vector<vector<ll>>
#define vpii vector<pair<int,int>>
#define vpll vector<pair<ll,ll>>
#define vb vector<bool>
#define vs vector<string>
///............x...........///
#define all(a) a.begin(), a.end()
#define allr(a) a.rbegin(), a.rend()
#define mp(a, b) make_pair(a, b)
#define pb push_back
#define ff first
#define ss second
#define bg begin()
#define UNIQUE(X) (X).erase(unique(all(X)), (X).end())
#define ft cout << "for test"<<endl;
#define read(v, a, n) for (int i = a; i<n; i++)cin>>v[i];
#define print(v) for (auto it : v)cout << it<<' ';cout << endl;
#define PI acos(-1.0)
#define yes cout <<"Yes"<< endl
#define no cout<<"No"<<endl
#define FIO ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define t_c int test, cs = 1;cin>>test;while (test--)
#define casep cout<<"Case "<< cs++<<": ";
///................function.....................///
#define D(a) (double)(a)
#define sqr(a) (a * a)
#define siz(s) (int)(s.size())
#define max3(a, b, c) max(a, max(b, c))
#define min3(a, b, c) min(a, min(b, c))
#define Min(a) *min_element(all(a))
///#define mod 1000000007
///.........Graph.........///
int X[] = {1, -1, 0, 0};
int Y[] = {0, 0, 1, -1};
///........constant........///
const ll N = 1e6+5;
int main(){
FIO;
int n;
while(cin>>n and n){
vi v(n+1);
vi store(n+1);
int i,j,a,b;
string s;
for(i=1; i<=n; i++){
cin>>a>>s;
v[i]= a;
store[i]=(s=="true");
}
bool hobe=1;
for(i=1; i<=n&&hobe; i++){
queue<int>q;
vi vis(n+1,-1);
vis[i]=1;
q.push(i);
while(!q.empty()){
int u = q.front();
q.pop();
int it = v[u];
if(vis[it]!=-1){
if(vis[u] and store[u]!=vis[it])
hobe=0;
else if(!vis[u] and store[u]==vis[it])
hobe=0;
break;
}
if(vis[u])vis[it]=store[u];
else vis[it]=!store[u];
q.push(it);
}
}
if(hobe)cout<<"NOT PARADOX"<<endl;
else cout<<"PARADOX"<<endl;
}
}