#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <cmath>

#include <bits/stdc++.h>

#include <stack>

#include <map>

using namespace std;

#define For(i,j,n) for(int i=j;i<=n;i++)

#define mst(ss,b) memset(ss,b,sizeof(ss));

#define ll long long;

typedef  long long LL;

template<class T> void read(T&num) {

    char CH; bool F=false;

    for(CH=getchar();CH<'0'||CH>'9';F= CH=='-',CH=getchar());

    for(num=0;CH>='0'&&CH<='9';num=num*10+CH-'0',CH=getchar());

    F && (num=-num);

}

int stk[70], tp;

template<class T> inline void print(T p) {

    if(!p) { puts("0"); return; }

    while(p) stk[++ tp] = p%10, p/=10;

    while(tp) putchar(stk[tp--] + '0');

    putchar('\n');

}

const LL mod=1e9+7;

const double PI=acos(-1.0);

const LL inf=1e18;

const int N=1e6+2000;

const int maxn=110;

const double eps=1e-8;

int n,u,v,num[110];

vector<int>ve[110];

double a[maxn][maxn],ans[maxn];

int in[maxn],d[maxn];

inline void Init()

{

    For(i,1,n)num[i]=ve[i].size();

    For(i,1,n+1)For(j,1,n+1)a[i][j]=0;

    for(int i=1;i<=n;i++)

    {

        a[i][i]=1;

        for(int j=0;j<num[i];j++)

        {

            a[i][ve[i][j]]-=1.0/d[ve[i][j]];

        }

        if(i==1)a[i][n+1]=1;

    }

}

void gauss()

{

    for(int i=1;i<=n;i++)

    {

        int r=i;

        for(int j=i+1;j<=n;j++)if(fabs(a[j][i])>fabs(a[r][i]))r=j;

        if(fabs(a[r][i])<eps)continue;

        if(r!=i)for(int j=0;j<=n+1;j++)swap(a[r][j],a[i][j]);

        for(int k=1;k<=n;k++)

        {

            if(k==i)continue;

            for(int j=n+1;j>=i;j--)a[k][j]-=a[k][i]/a[i][i]*a[i][j];

        }

     }

}

int main()

{

    int Case=0;

    while(1)

    {

        read(n);

        if(!n)break;

        printf("Case #%d:\n",++Case);

        For(i,1,n)ve[i].clear(),d[i]=0;

        while(1)

        {

            read(u);read(v);

            if(!u&&!v)break;

            d[u]++;

            ve[v].push_back(u);

        }

        Init();

        gauss();

        mst(in,0);

        for(int i=n;i>0;i--)

        {

            if(fabs(a[i][i])<eps&&fabs(a[i][n+1])>eps)in[i]=1;

            for(int j=i+1;j<=n;j++)

                if(fabs(a[i][j])>eps&&in[j])in[i]=1;

        }

        int q,x;

        read(q);

        while(q--)

        {

            read(x);

            if(in[x])printf("infinity\n");

            else printf("%.3lf\n",fabs(a[x][x])<eps? 0.0:a[x][n+1]/a[x][x]);

        }

    }

    return 0;

}