1 #include <cstdio>
  2 #include <algorithm>
  3
  4 const int N = 100010;
  5
  6 int fa[N], s[N][2], col[N], sum[N], lc[N], rc[N], S[N], Sp, tag[N];
  7 bool rev[N];
  8
  9 inline bool no_root(int x) {
 10     return (s[fa[x]][0] == x) || (s[fa[x]][1] == x);
 11 }
 12
 13 inline void pushdown(int x) {
 14     int ls = s[x][0], rs = s[x][1];
 15     if(rev[x]) {
 16         if(ls) {
 17             rev[ls] ^= 1;
 18             std::swap(lc[ls], rc[ls]);
 19         }
 20         if(rs) {
 21             rev[rs] ^= 1;
 22             std::swap(lc[rs], rc[rs]);
 23         }
 24         std::swap(s[x][0], s[x][1]);
 25         rev[x] = 0;
 26     }
 27     if(tag[x]) {
 28         int c = tag[x];
 29         if(ls) {
 30             tag[ls] = col[ls] = lc[ls] = rc[ls] = c;
 31             sum[ls] = 0;
 32         }
 33         if(rs) {
 34             tag[rs] = col[rs] = lc[rs] = rc[rs] = c;
 35             sum[rs] = 0;
 36         }
 37         tag[x] = 0;
 38     }
 39     return;
 40 }
 41
 42 inline void pushup(int x) {
 43     int ls = s[x][0], rs = s[x][1];
 44     pushdown(ls);
 45     pushdown(rs);
 46     sum[x] = sum[ls] + sum[rs];
 47     if(ls) {
 48         lc[x] = lc[ls];
 49         if(rc[ls] != col[x]) {
 50             sum[x]++;
 51         }
 52     }
 53     else {
 54         lc[x] = col[x];
 55     }
 56     if(rs) {
 57         rc[x] = rc[rs];
 58         if(lc[rs] != col[x]) {
 59             sum[x]++;
 60         }
 61     }
 62     else {
 63         rc[x] = col[x];
 64     }
 65     return;
 66 }
 67
 68 inline void rotate(int x) {
 69     int y = fa[x];
 70     int z = fa[y];
 71     bool f = (s[y][1] == x);
 72
 73     fa[x] = z;
 74     if(no_root(y)) {
 75         s[z][s[z][1] == y] = x;
 76     }
 77     s[y][f] = s[x][!f];
 78     if(s[x][!f]) {
 79         fa[s[x][!f]] = y;
 80     }
 81     s[x][!f] = y;
 82     fa[y] = x;
 83
 84     pushup(y);
 85     pushup(x);
 86     return;
 87 }
 88
 89 inline void splay(int x) {
 90     int y = x;
 91     S[++Sp] = y;
 92     while(no_root(y)) {
 93         y = fa[y];
 94         S[++Sp] = y;
 95     }
 96     while(Sp) {
 97         pushdown(S[Sp]);
 98         Sp--;
 99     }
100
101     y = fa[x];
102     int z = fa[y];
103     while(no_root(x)) {
104         if(no_root(y)) {
105             (s[z][1] == y) ^ (s[y][1] == x) ?
106             rotate(x) : rotate(y);
107         }
108         rotate(x);
109         y = fa[x];
110         z = fa[y];
111     }
112     return;
113 }
114
115 inline void access(int x) {
116     int y = 0;
117     while(x) {
118         splay(x);
119         s[x][1] = y;
120         pushup(x);
121         y = x;
122         x = fa[x];
123     }
124     return;
125 }
126
127 inline void make_root(int x) {
128     access(x);
129     splay(x);
130     rev[x] = 1;
131     return;
132 }
133
134 inline int find_root(int x) {
135     access(x);
136     splay(x);
137     while(s[x][0]) {
138         x = s[x][0];
139         pushdown(x);
140     }
141     return x;
142 }
143
144 inline void link(int x, int y) {
145     make_root(x);
146     fa[x] = y;
147     return;
148 }
149
150 inline void cut(int x, int y) {
151     make_root(x);
152     access(y);
153     splay(y);
154     fa[x] = s[y][0] = 0;
155     pushup(y);
156     return;
157 }
158
159 inline void change(int x, int y, int c) {
160     make_root(x);
161     access(y);
162     splay(y);
163     tag[y] = col[y] = lc[y] = rc[y] = c;
164     sum[y] = 0;
165     return;
166 }
167
168 inline int ask(int x, int y) {
169     make_root(x);
170     access(y);
171     splay(y);
172     return sum[y] + 1;
173 }
174
175 char str[10];
176
177 int main() {
178     int n, m;
179     scanf("%d%d", &n, &m);
180     for(int i = 1; i <= n; i++) {
181         scanf("%d", &col[i]);
182         lc[i] = rc[i] = col[i];
183     }
184     for(int i = 1, x, y; i < n; i++) {
185         scanf("%d%d", &x, &y);
186         link(x, y);
187     }
188
189     for(int i = 1, x, y, z; i <= m; i++) {
190         scanf("%s%d%d", str, &x, &y);
191         if(str[0] == 'C') {
192             scanf("%d", &z);
193             change(x, y, z);
194         }
195         else {
196             int t = ask(x, y);
197             printf("%d\n", t);
198         }
199     }
200
201     return 0;
202 }