1 {$M 10000000,0,maxlongint}
2 const maxn=100000+10;
3 type node1=record
4 go,next:longint;
5 end;
6 node2=record
7 l,r,mid,lch,rch,mx:longint;
8 sum:int64;
9 end;
10
11 var e:array[0..2*maxn] of node1;
12 t:array[0..40*maxn] of node2;
13 p,fa,s,head,dep,son,top,w,c,rt:array[0..maxn] of longint;
14 i,n,m,x,y,z,sz,tot,cnt,root:longint;
15 ans:int64;
16 ch:char;
17 procedure swap(var x,y:longint);
18 var t:longint;
19 begin
20 t:=x;x:=y;y:=t;
21 end;
22 procedure insert(x,y:longint);
23 begin
24 inc(tot);
25 e[tot].go:=y;e[tot].next:=head[x];head[x]:=tot;
26 end;
27 function min(x,y:longint):longint;
28 begin
29 if x<y then exit(x) else exit(y);
30 end;
31 function max(x,y:longint):longint;
32 begin
33 if x>y then exit(x) else exit(y);
34 end;
35 procedure dfs1(x:longint);
36 var i,j,y:longint;
37 begin
38 j:=0;s[x]:=1;
39 i:=head[x];
40 while i<>0 do
41 begin
42 y:=e[i].go;
43 if dep[y]=0 then
44 begin
45 dep[y]:=dep[x]+1;
46 fa[y]:=x;
47 dfs1(y);
48 inc(s[x],s[y]);
49 if s[y]>s[j] then j:=y;
50 end;
51 i:=e[i].next;
52 end;
53 son[x]:=j;
54 end;
55 procedure dfs2(x,chain:longint);
56 var i,y:longint;
57 begin
58 inc(sz);p[x]:=sz;top[x]:=chain;
59 if son[x]<>0 then dfs2(son[x],chain);
60 i:=head[x];
61 while i<>0 do
62 begin
63 y:=e[i].go;
64 if (y<>son[x]) and (y<>fa[x]) then dfs2(y,y);
65 i:=e[i].next;
66 end;
67 end;
68 procedure pushup(k:longint);
69 begin
70 with t[k] do
71 begin
72 mx:=max(t[lch].mx,t[rch].mx);
73 sum:=t[lch].sum+t[rch].sum;
74 end;
75 end;
76 procedure change(var k:longint;x,y,pos,val:longint);
77 begin
78 if k=0 then begin inc(cnt);k:=cnt;end;
79 with t[k] do
80 begin
81 l:=x;r:=y;mid:=(l+r)>>1;
82 if l=r then begin mx:=val;sum:=val;exit;end;
83 if pos<=mid then change(lch,l,mid,pos,val)
84 else change(rch,mid+1,r,pos,val);
85 pushup(k);
86 end;
87 end;
88 procedure init;
89 begin
90 readln(n,m);
91 for i:=1 to n do readln(w[i],c[i]);
92 for i:=1 to n-1 do begin readln(x,y);insert(x,y);insert(y,x);end;
93 dep[1]:=1;
94 dfs1(1);
95 dfs2(1,1);
96 cnt:=0;
97 for i:=1 to n do change(rt[c[i]],1,n,p[i],w[i]);
98 end;
99 function getmx(k,x,y:longint):longint;
100 begin
101 if k=0 then exit(0);
102 with t[k] do
103 begin
104 if (l=x) and (r=y) then exit(mx);
105 if y<=mid then exit(getmx(lch,x,y))
106 else if x>mid then exit(getmx(rch,x,y))
107 else exit(max(getmx(lch,x,mid),getmx(rch,mid+1,y)));
108 end;
109 end;
110 function getsum(k,x,y:longint):int64;
111 begin
112 if k=0 then exit(0);
113 with t[k] do
114 begin
115 if (l=x) and (r=y) then exit(sum);
116 if y<=mid then exit(getsum(lch,x,y))
117 else if x>mid then exit(getsum(rch,x,y))
118 else exit(getsum(lch,x,mid)+getsum(rch,mid+1,y));
119 end;
120 end;
121 procedure solvemx;
122 begin
123 ans:=0;
124 readln(x,y);root:=rt[c[x]];
125 while top[x]<>top[y] do
126 begin
127 if dep[top[x]]<dep[top[y]] then swap(x,y);
128 ans:=max(ans,getmx(root,p[top[x]],p[x]));
129 x:=fa[top[x]];
130 end;
131 if dep[x]>dep[y] then swap(x,y);
132 ans:=max(ans,getmx(root,p[x],p[y]));
133 writeln(ans);
134 end;
135 procedure solvesum;
136 begin
137 ans:=0;
138 readln(x,y);root:=rt[c[x]];
139 while top[x]<>top[y] do
140 begin
141 if dep[top[x]]<dep[top[y]] then swap(x,y);
142 inc(ans,getsum(root,p[top[x]],p[x]));
143 x:=fa[top[x]];
144 end;
145 if dep[x]>dep[y] then swap(x,y);
146 inc(ans,getsum(root,p[x],p[y]));
147 writeln(ans);
148 end;
149 procedure main;
150 begin
151 for i:=1 to m do
152 begin
153 read(ch,ch);
154 case ch of
155 ‘W‘:begin
156 readln(x,y);
157 w[x]:=y;
158 change(rt[c[x]],1,n,p[x],y);
159 end;
160 ‘C‘:begin
161 readln(x,y);
162 change(rt[c[x]],1,n,p[x],0);
163 c[x]:=y;
164 change(rt[y],1,n,p[x],w[x]);
165 end;
166 ‘M‘:solvemx;
167 ‘S‘:solvesum;
168 end;
169 end;
170 end;
171 begin
172 assign(input,‘input.txt‘);assign(output,‘output.txt‘);
173 reset(input);rewrite(output);
174 init;
175 main;
176 close(input);close(output);
177 end.
