#include <iostream>
#include <cstdio>
#include <string.h>
#include <queue>
#include <algorithm>
#include <math.h>
using namespace std;
typedef long long LL;
const int INF = 999999999;
const int N = 1000;
struct Edge{
    int v,w,next;
}edge[10005];
int head[N];
int n,tot;
int val[N];
void init(){
    memset(head,-1,sizeof(head));
    tot = 0;
}
void addEdge(int u,int v,int w,int &k){
    edge[k].v = v,edge[k].w = w,edge[k].next = head[u],head[u] = k++;
}
int low[N],time[N];
bool vis[N];
int spfa(int s){
    for(int i=0;i<=n;i++){
        vis[i] = false;
        low[i] = -INF;
        time[i] = 0;
    }
    low[s] = 0;
    time[s]++;
    queue<int> q;
    q.push(s);
    int num = ((int)sqrt(n)+1);  ///改成根号 n 可以AC...
    while(!q.empty()){
        int u = q.front();
        q.pop();
        vis[u] = false;
        for(int k=head[u];k!=-1;k=edge[k].next){
            int v = edge[k].v,w=edge[k].w;
            if(low[v]<low[u]+w){
                low[v] = low[u]+w;
                if(!vis[v]){
                    vis[v] = true;
                    q.push(v);
                    if(time[v]++>num) return 0;
                }
            }
        }
    }
    return 1;
}
int main(){
    int t = 1;
    while(scanf("%d",&n)!=EOF,n){
        init();
        int MAX = -1;
        for(int i=1;i<=n;i++){
            scanf("%d",&val[i]);
        }
        char str[10];
        int super = 0;
        while(scanf("%s",str)){
            if(strcmp(str,"#")==0) break;
            int a,b;
            scanf("%d%d",&a,&b);
            if(strcmp(str,"SAF")==0){
                addEdge(b,a,val[b],tot);
            }else if(strcmp(str,"FAF")==0){
                addEdge(b,a,-(val[a]-val[b]),tot);
            }else if(strcmp(str,"FAS")==0){
                addEdge(b,a,-val[a],tot);
            }else{
                addEdge(b,a,0,tot);
            }
        }
        for(int i=1;i<=n;i++){
            addEdge(super,i,0,tot);
        }
        printf("Case %d:\n",t++);
        if(spfa(super)){
            for(int i=1;i<=n;i++){
                printf("%d %d\n",i,low[i]);
            }
        }else{
            printf("impossible\n");
        }
        printf("\n");
    }
    return 0;
}