1 #include <stdio.h>
 2 #include <string.h>
 3 #include <iostream>
 4 #include <vector>
 5 using namespace std;
 6 
 7 vector<pair<int,int> >v;
 8 vector<int>s[1005];
 9 
10 int father[1005];
11 int down[1005],up[1005];
12 char ans[1005];
13 
14 int Find(int x)
15 {
16     if(father[x]!=x)
17         return father[x] = Find(father[x]);
18     return father[x];
19 }
20 
21 
22 void unio(int a,int b)
23 {
24     int root1 = Find(a);
25     int root2 = Find(b);
26     if(root1!=root2)
27         father[root1] = root2;
28 }
29 
30 int main()
31 {
32   //  freopen("input.txt","r",stdin);
33   // freopen("output.txt","w",stdout);
34     int m,n;
35     int a,b;
36     char c;
37     scanf("%d%d",&m,&n);
38     for(int i = 1;i<=m;i++)
39     {
40         father[i] = i;
41         ans[i]=‘?‘;
42     }
43     for(int i = 0;i<n;i++)
44     {
45         scanf("%d%c%d",&a,&c,&b);
46         if(c==‘=‘)
47             unio(a,b);
48         else {
49             if(c==‘>‘)
50                 swap(a,b);
51             v.push_back(make_pair(a,b));
52         }
53     }
54     for(int i = 1;i<=m;i++)
55     {
56         Find(i);
57         s[Find(i)].push_back(i);
58     }
59     for(int i = 0;i<v.size();i++)
60     {
61         a = v[i].first;
62         b = v[i].second;
63         down[Find(a)]++;
64         up[Find(b)]++;
65     }
66     for(int i =1;i<=m;i++)
67     {
68         if(down[Find(i)]&&up[Find(i)])
69         {
70             for(int j = 0;j<s[Find(i)].size();j++)
71             {
72                 ans[s[Find(i)][j]] = ‘R‘;
73             }
74             s[Find(i)].clear();
75         }
76     }
77     for(int i = 0;i<v.size();i++)
78     {
79         a = v[i].first;
80         b = v[i].second;
81         if(ans[a]==‘R‘){
82             for(int j = 0;j<s[Find(b)].size();j++)
83                 ans[s[Find(b)][j]] = ‘W‘;
84             s[Find(b)].clear();
85         }else if(ans[b]==‘R‘){
86             for(int j = 0;j<s[Find(a)].size();j++)
87                 ans[s[Find(a)][j]]=‘B‘;
88             s[Find(a)].clear();
89         }
90     }
91     for(int i = 1;i<=m;i++)
92         printf("%c",ans[i]);
93     printf("\n");
94     return 0;
95 }