1 #include<cstdio>
2 #include<cstdlib>
3 #include<cmath>
4 #include<cstring>
5 #include<algorithm>
6 #include<iostream>
7 #include<vector>
8 #include<map>
9 #include<set>
10 #include<queue>
11 #include<string>
12 #define inf 1000000000
13 #define maxn 100000+5
14 #define maxm 500+100
15 #define eps 1e-10
16 #define ll long long
17 #define pa pair<int,int>
18 #define for0(i,n) for(int i=0;i<=(n);i++)
19 #define for1(i,n) for(int i=1;i<=(n);i++)
20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
22 #define mod 1000000007
23 using namespace std;
24 inline int read()
25 {
26 int x=0,f=1;char ch=getchar();
27 while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
28 while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
29 return x*f;
30 }
31 int n,m,v[maxn],sum[maxn],c[maxn][2],fa[maxn],f[maxn],sta[maxn],top;
32 bool rev[maxn];
33 inline int find(int x){return f[x]==x?x:f[x]=find(f[x]);}
34 inline bool isroot(int x)
35 {
36 return c[fa[x]][0]!=x&&c[fa[x]][1]!=x;
37 }
38 inline void pushup(int x)
39 {
40 sum[x]=sum[c[x][0]]+sum[c[x][1]]+v[x];
41 }
42 inline void rever(int x)
43 {
44 rev[x]^=1;swap(c[x][0],c[x][1]);
45 }
46 inline void pushdown(int x)
47 {
48 if(!rev[x])return;
49 rever(c[x][0]);rever(c[x][1]);
50 rev[x]=0;
51 }
52 inline void rotate(int x)
53 {
54 int y=fa[x],z=fa[y],l=c[y][1]==x,r=l^1;
55 if(!isroot(y))c[z][c[z][1]==y]=x;
56 fa[x]=z;fa[y]=x;fa[c[x][r]]=y;
57 c[y][l]=c[x][r];c[x][r]=y;
58 pushup(y);pushup(x);
59 }
60 inline void splay(int x)
61 {
62 sta[++top]=x;
63 for(int y=x;!isroot(y);y=fa[y])sta[++top]=fa[y];
64 for(;top;)pushdown(sta[top--]);
65 while(!isroot(x))
66 {
67 int y=fa[x],z=fa[y];
68 if(!isroot(y))
69 {
70 if(c[z][0]==y^c[y][0]==x)rotate(x);else rotate(y);
71 }
72 rotate(x);
73 }
74 }
75 inline void access(int x)
76 {
77 for(int y=0;x;x=fa[x])
78 {
79 splay(x);c[x][1]=y;pushup(x);y=x;
80 }
81 }
82 inline void makeroot(int x)
83 {
84 access(x);splay(x);rever(x);
85 }
86 inline void link(int x,int y)
87 {
88 if(find(x)==find(y)){printf("no\n");return;}
89 printf("yes\n");
90 makeroot(x);fa[x]=y;f[find(x)]=find(y);splay(x);
91 }
92 inline void split(int x,int y)
93 {
94 makeroot(x);access(y);splay(y);
95 }
96 int main()
97 {
98 freopen("input.txt","r",stdin);
99 freopen("output.txt","w",stdout);
100 n=read();
101 for1(i,n)v[i]=sum[i]=read(),f[i]=i;
102 m=read();
103 while(m--)
104 {
105 char ch[10];
106 scanf("%s",ch);int x=read(),y=read();
107 if(ch[0]==‘b‘)link(x,y);
108 else if(ch[0]==‘p‘)splay(x),v[x]=y,pushup(x);
109 else if(find(x)!=find(y))printf("impossible\n");
110 else split(x,y),printf("%d\n",sum[y]);
111 }
112 return 0;
113 }
