1 #include<iostream>
  2 #include<cstdio>
  3 #include<cstring>
  4 #include<queue>
  5 using namespace std;
  6 queue<int>pq;
  7 struct edge{
  8     int to;
  9     int next;
 10 }EDGE[20005];
 11 struct pot{
 12     int to1;
 13     int to2;
 14     char ch;
 15 }POT[20005];
 16 int cnt=0;    
 17 int flag;
 18 int in[10005],head[10005],pre[10005],vis[10005],vviss[10005],vvis[10005],out[10005];
 19 int n,m,N;
 20 void add(int x,int y)
 21 {
 22     in[y]++;
 23     out[x]++;
 24     EDGE[cnt].to=y;
 25     EDGE[cnt].next=head[x];
 26     head[x]=cnt++;
 27 }
 28 int orz1=0,orz2=0;
 29 int find(int x)
 30 {
 31     int xx=x;
 32     while(x!=pre[x])
 33     {
 34         x=pre[x];
 35     }
 36     while(pre[xx]!=x)
 37     {
 38         int t=pre[xx];
 39         pre[xx]=x;
 40         xx=t;
 41     }
 42     return x;
 43 }
 44 void Topsort()
 45 {
 46     int wqw=0;
 47     for(int i = 0 ; i < N ; i++)
 48     {
 49         if(!in[find(i)]&&!vis[find(i)])
 50         {
 51             wqw++;
 52             orz2++;
 53             vis[find(i)]=1;
 54             pq.push(find(i));
 55         }
 56     }
 57     if(wqw>1)flag=2;
 58     while(!pq.empty())
 59     {
 60         int qwq=pq.front();pq.pop();
 61         for(int i = head[qwq];i != -1 ; i=EDGE[i].next)
 62         {
 63             int v=EDGE[i].to;
 64             in[v]--;
 65             if(!in[v])
 66             {
 67                 orz2++;
 68                 pq.push(v);
 69             }
 70         }
 71     }
 72 }
 73 int main()
 74 {
 75     while(scanf("%d%d",&n,&m)==2)
 76     {
 77         N=n;
 78         orz1=0;orz2=0;
 79         memset(head,-1,sizeof(head));
 80         memset(vis,0,sizeof(vis));
 81         memset(vvis,0,sizeof(vvis));
 82         memset(vviss,0,sizeof(vviss));
 83         memset(in,0,sizeof(in));
 84         memset(out,0,sizeof(out));
 85         for(int i = 0 ; i < n ; i++)pre[i]=i;
 86         for(int i = 0 ; i < m; i++)
 87         {
 88             int a,c;
 89             char b;
 90             scanf("%d %c %d",&POT[i].to1,&POT[i].ch,&POT[i].to2);
 91             if(POT[i].ch==‘=‘)
 92             {
 93                 if(find(POT[i].to1)!=find(POT[i].to2))
 94                 {
 95                     pre[find(POT[i].to1)]=find(POT[i].to2);
 96                     n--;
 97                 }
 98             //    vviss[find(POT[i].to2)]=1;
 99             }    
100         }
101         flag=0;
102     for(int i = 0 ; i < m ; i++)
103     {
104         if(POT[i].ch==‘=‘)
105         continue;
106         char b=POT[i].ch;
107         int a=find(POT[i].to1);
108         int c=find(POT[i].to2);
109         if(a!=c)
110         {
111             if(b==‘>‘)
112                 add(a,c);
113                 else if(b==‘<‘)
114                 add(c,a);        
115         
116         }
117         else
118         flag=3;
119     }
120     int qwq=0;
121     if(flag!=3)
122     {
123     for(int i = 0 ; i < N ; i++)
124     {
125         if(!out[find(i)]&&!vvis[find(i)])
126         {
127             vvis[find(i)]=1;
128             qwq++;
129             if(qwq>1){
130             flag=2;
131             break;}
132         }
133     }
134     Topsort();
135     if(orz2<n)flag=3;
136 }
137     if(flag==2)printf("UNCERTAIN\n");
138     else if(flag==3)printf("CONFLICT\n");
139     else printf("OK\n");
140     }
141 
142     return 0;
143 }