UVA 12970

/**************************************************
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   |||    |||    |||___|||     |||____|||   |||
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***************************************************/
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <sstream>
#include <algorithm>
#include <ctime>
#include <cassert>
#include <limits>
using  namespace  std;

#define PI acos(-1.0)
#define mem(a,b) memset(a,b,sizeof(a))
#define gcd(a,b) __gcd(a,b)
#define pb push_back
#define mp make_pair
#define x first
#define y second
#define Sort(x) sort(x.begin(),x.end())
#define FOR(i, b, e) for(int i = b; i <= e; i++)
#define FORR(i, b, e) for(int i = b; i >= e; i--)
#define FORI(i, s) for (__typeof ((s).end ()) i = (s).begin (); i != (s).end (); ++i)
#define pr(x) cout<<x<<"\n"
#define pr2(x,y) cout<<x<<" "<<y<<"\n"
#define pr3(x,y,z) cout<<x<<" "<<y<<" "<<z<<"\n";
#define ppr(a) cout<<a.x<<" "<<a.y<<"\n"
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)

typedef  long long ll;
typedef  pair <int, int> pii;
typedef  pair <double , double> pdd;
typedef  pair <ll , ll > pll;
typedef  vector <int> vi;
typedef  vector <pii> vpii;
typedef  vector <ll > vl;

//int dx[]={1,0,-1,0};int dy[]={0,1,0,-1}; //4 Direction
//int dx[]={1,1,0,-1,-1,-1,0,1};
//int dy[]={0,1,1,1,0,-1,-1,-1};//8 direction
//int dx[]={2,1,-1,-2,-2,-1,1,2};
//int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction

#define MAX 50007
#define EPS 1e-9
ll gcdll(ll a, ll b){
  if(b == 0) return a;
  return gcdll(b, a%b);
}
int main()
{
    //READ("in.in");
    //WRITE("out.out");
    ll v1,v2,d1,d2;
    int cs=1;
    while(1)
    {

        scanf("%lld",&v1);
        scanf("%lld",&d1);
        scanf("%lld",&v2);
        scanf("%lld",&d2);
        if(v1==0&&d1==0&&v2==0&&d2==0)break;
        if(d1*v2<=d2*v1)
        {
            printf("Case #%d: You owe me a beer!\nAvg. arrival time: ",cs++);
        }
        else
        {
            printf("Case #%d: No beer for the captain.\nAvg. arrival time: ",cs++);
        }
        v1*=2;
        v2*=2;
        ll g=gcdll(d1,v1);
        d1/=g;
        v1/=g;
        g=gcdll(d2,v2);
        d2/=g;
        v2/=g;
        ll lcm=(v1/gcd(v1,v2))*v2;
        ll lob=d1*(lcm/v1)+d2*(lcm/v2);
        g=gcdll(lcm,lob);
        lcm/=g;
        lob/=g;
        printf("%lld",lob);
        if(lcm!=1)printf("/%lld",lcm);
        printf("\n");
    }
    return 0;
}