1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstdlib>
  4 #include <cmath>
  5 #include <vector>
  6 #include <ctime>
  7 #include <map>
  8 #include <stack>
  9 #include <queue>
 10 #include <cstring>
 11 #include <algorithm>
 12 using namespace std;
 13 
 14 #define sacnf scanf
 15 #define scnaf scanf
 16 #define maxn  10010
 17 #define maxm 26
 18 #define inf 1061109567
 19 #define Eps 0.00001
 20 const double PI=acos(-1.0);
 21 #define mod 1000033
 22 #define MAXNUM 10000
 23 void Swap(int &a,int &b) {int t=a;a=b;b=t;}
 24 int Abs(int x) {return (x<0)?-x:x;}
 25 typedef long long ll;
 26 typedef unsigned int uint;
 27 
 28 struct node
 29 {
 30     int from,to;
 31     char cmp;
 32 } edge[maxn];
 33 
 34 vector<int> G[maxn];
 35 int in[maxn],ans[maxn],p[maxn],cnt,equals;
 36 
 37 int found(int x) {return (p[x]==x)?x:p[x]=found(p[x]);}
 38 
 39 void toposort(int n)
 40 {
 41     queue<int> q;
 42     for(int i=0;i<n;i++)
 43         if(i==p[i]&&!in[i]) q.push(i);
 44     cnt=0;
 45     while(!q.empty())
 46     {
 47         int u=q.front();q.pop();
 48         ans[cnt++]=u;
 49         int len=G[u].size();
 50         for(int i=0;i<len;i++)
 51         {
 52             int v=G[u][i];
 53             in[v]--;
 54             if(!in[v]) q.push(v);
 55         }
 56     }
 57 }
 58 
 59 void re_toposort(int n)
 60 {
 61     if(cnt<n-equals) {printf("CONFLICT\n");return;}
 62     priority_queue<int,vector<int>,greater<int> > q;
 63     for(int i=0;i<n;i++)
 64         if(i==p[i]&&!in[i]) q.push(i);
 65     while(!q.empty())
 66     {
 67         int u=q.top();q.pop();
 68         if(ans[--cnt]!=u) {printf("UNCERTAIN\n");return;}
 69         int len=G[u].size();
 70         for(int i=0;i<len;i++)
 71         {
 72             int v=G[u][i];
 73             in[v]--;
 74             if(!in[v]) q.push(v);
 75         }
 76     }
 77     printf("OK\n");
 78 }
 79 
 80 int main()
 81 {
 82     //freopen("data.in","r",stdin);
 83     //freopen("flyer.out","w",stdout);
 84     //clock_t st=clock();
 85     int n,m;
 86     while(~scanf("%d%d",&n,&m))
 87     {
 88         for(int i=0;i<n;i++) {G[i].clear();in[i]=0;p[i]=i;}
 89         int a,c;char b;equals=0;
 90         for(int i=1;i<=m;i++)
 91         {
 92             scanf("%d %c %d",&edge[i].from,&edge[i].cmp,&edge[i].to);
 93             a=edge[i].from;b=edge[i].cmp;c=edge[i].to;
 94             if(b==‘=‘)
 95             {
 96                 int x=found(a);
 97                 int y=found(c);
 98                 if(x!=y) {p[x]=y;equals++;}
 99             }
100         }
101         for(int i=1;i<=m;i++)
102         {
103             a=edge[i].from;b=edge[i].cmp;c=edge[i].to;
104             a=found(a);c=found(c);
105             if(b==‘<‘) {G[c].push_back(a);in[a]++;}
106             else if(b==‘>‘) {G[a].push_back(c);in[c]++;}
107         }
108         /*for(int i=0;i<n;i++)
109         {
110             printf("%d :",i);
111             int len=G[i].size();
112             for(int j=0;j<len;j++)
113             {
114                 printf(" %d",G[i][j]);
115             }
116             printf("     %d\n",in[i]);
117         }*/
118         toposort(n);
119         for(int i=0;i<n;i++) {G[i].clear();in[i]=0;}
120         for(int i=1;i<=m;i++)
121         {
122             a=edge[i].from;b=edge[i].cmp;c=edge[i].to;
123             a=found(a);c=found(c);
124             if(b==‘<‘) {G[a].push_back(c);in[c]++;}
125             else if(b==‘>‘) {G[c].push_back(a);in[a]++;}
126         }
127         re_toposort(n);
128     }
129     //clock_t ed=clock();
130     //printf("\n\nTime Used : %.5lf Ms.\n",(double)(ed-st)/CLOCKS_PER_SEC);
131     return 0;
132 }