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#include <iostream>
#include <cstdio>
using namespace std;
const int INF = 1<<30;
const int maxn = 30233;
typedef long long LL;
int getint() {
	int r = 0, k = 1; char c = getchar();
	for (; '0' > c || c > '9'; c = getchar()) if (c == '-') k = -1;
	for (; '0' <= c && c <= '9'; c = getchar()) r = r * 10 - '0' + c;
	return r * k;
}
char getop() {
	char c;
	for (c = getchar(); 'a' > c || c > 'z'; c = getchar());
	return c;
}
int n,m;
int rev[maxn],sum[maxn],c[maxn][2],p[maxn],fa[maxn];
void pd(int x) {
	if (rev[x]) {
		rev[c[x][0]]^=1;rev[c[x][1]]^=1;rev[x]=0;
		swap(c[x][0],c[x][1]);
	}
}
void pu(int x) {
	sum[x] = sum[c[x][0]]+sum[c[x][1]]+p[x];
}
bool isroot(int x){
	return c[fa[x]][0]!=x&&c[fa[x]][1]!=x;
}
int ws(int x) {
	return c[fa[x]][1]==x;
}
void rotate(int x) {
	int y=fa[x],z=fa[y],a=ws(x),b=!a;
	if(!isroot(y)){
		if(y==c[z][0]) c[z][0]=x;
		else c[z][1]=x;
	}
	fa[x]=z;fa[y]=x;fa[c[x][b]]=y;
	c[y][a]=c[x][b];c[x][b]=y;
	pu(y); pu(x);
}
int st[maxn];
void splay(int x) {
	int tail = 1; st[1] = x;
	for (int i=x;!isroot(i);i=fa[i]) st[++tail]=fa[i];
	while(tail) pd(st[tail--]);
	while (!isroot(x)) {
		int y=fa[x],z=fa[y];
		if(!isroot(y)){
			if(c[y][0]==x^c[z][0]==y)rotate(x);
			else rotate(y);
		}
		rotate(x);
	}
}
void access(int x){
	int y = 0;
	while(x) {
		splay(x);
		c[x][1]=y;
		pu(x); //Attention!
		y=x;x=fa[x];
	}
}
void mkrt(int x) {
	access(x); splay(x); rev[x] ^= 1;
}
void link(int u,int v) {
	mkrt(u);
	fa[u]=v;
	splay(u);
}
void cut(int u,int v) {
	mkrt(u);
	access(v);
	splay(v);
	fa[u]=0;
	c[v][0]=0;
}
int ask(int x, int y) {
	mkrt(x);
	access(y);
	splay(y);
	return sum[y];// 
}
void change(int pos, int x) {
	mkrt(pos);
	p[pos]=x;
	pu(pos);
}
int findrt(int x) {
	access(x); splay(x); //Forgot
	while (c[x][0]) x = c[x][0];
	splay(x);
	return x;
}
int main() {
	n = getint();int x;
	for (int i = 1; i <= n; ++i) {
		x=getint();
		p[i]=sum[i]=x;
	}
	m=getint();
	char op; int y;
	while(m--) {
		op = getop();
		x = getint(); y = getint();
		if (op == 'b') {
			if (findrt(x)==findrt(y)) {
				printf("no\n");
			} else {
				printf("yes\n");
				link(x, y);
			}
			continue;
		}
		if (op == 'p'){
			change(x,y);
			continue;
		}
		if (findrt(x)!=findrt(y)) {
			printf("impossible\n");
		} else {
			printf("%d\n", ask(x,y));
		}
	}
	return 0;
}