/*
判断是否有合法解，最短路和最长路都行，这里采用最长路
P a b c:
s[ b ]-s[ a ]<=c -> s[ b ]-c<=s[a] - > G[ b ].push_back({a,-c});
s[ b ]-s[ a ]>=c -> s[ a ]+c<=s[ b ] -> G[a].push_back({b,c});

V a b:
s[ b ]-s[ a ]>=1 -> s[ a ]+1<=s[ b ] -> G[a].push_back({b,1})。
*/
#include<bits/stdc++.h>
using namespace std;
constexpr int N=1010;
vector< pair<int,int> > G[N];
int n,st,ed,d[N],dd[N];bool v[N];
int spfa()
{
    memset(d,0,sizeof(d));memset(dd,0,sizeof(dd));
    memset(v,0,sizeof(v));
    queue<int>q;
    for(int i=st;i<=ed;i++)q.push(i),v[i]=1;
    d[st]=0;
    while(!q.empty())
    {
        int x=q.front(); q.pop();v[x]=0;
        for(auto i:G[x])
        {
            int y=i.first,w=i.second;
            if(d[y]<d[x]+w)
            {
                d[y]=d[x]+w;
                dd[y]=dd[x]+1;if(dd[y]>n)return 0;
                if(v[y]==0) q.push(y),v[y]=1;
            }
        }
    }
    return 1;
}
int main()
{
    int m;
    while(scanf("%d",&n) && n)
    {
        scanf("%d",&m);
        memset(G ,0,sizeof(G));
        st=n+1;ed=0;
        for(int i=1,a,b,c;i<=m;i++)
        {
            char op[5];scanf("%s%d%d",op,&a,&b);
            if(op[0]=='P')
            {
                scanf("%d",&c);
                G[ b ].push_back({a,-c});
                G[a].push_back({b,c});
            }
            else G[a].push_back({b,1});
            st=min(st,min(a,b));
            ed=max(ed,max(a,b));
        }
        
        if( !spfa() ) printf("Reliable\n"); 
        else  printf("Unreliable\n");
    }
    return 0;
}