#include<iostream>
#include<string>
#include<cstring>
#include<algorithm>
using namespace std;
string date[100005];
char tmp[20];
//char week[10000][13][32];
int refl[15];
inline bool Leap(int year){if(year%400==0||(year%4==0 && year%100!=0))return 1;else return 0;
}
inline bool days31(int month){return (month==1 || month==3 || month==5 || month==7 || month==8 || month==10 || month==12);
}
inline bool Zeller(int year,int month,int day){if(year<1600)return 0;if(month==0 || month >=13)return 0;if(day<=0)return 0; if(month==2){if(Leap(year)){if(day>29)return 0;}else{if(day>28)return 0;}}if(days31(month)){if(day>31)return 0;}else{if(day>30)return 0;}//判断日期合法性 if (month == 1 || month == 2){year--;month += 12;}//判断month是否为1或2　int c = year / 100;int y = year - c * 100;int week = y + y / 4 + c / 4 - 2 * c + 26 * (month + 1) / 10 + day - 1;week%=7;week+=7;week%=7;return (week==5);
}
int main(){int T;scanf("%d",&T);for(int I=1;I<=T;I++){int n;scanf("%d",&n);for(int i=1;i<=n;i++){scanf("%s",tmp);
//            0000/00/00tmp[4]=0;tmp[7]=0;date[i].clear();date[i]+=tmp;date[i]+=tmp+5;date[i]+=tmp+8;}sort(date+1,date+1+n);n=unique(date+1,date+1+n)-date-1;//去重
//        printf("%d\n",n);for(int i=0;i<10;i++)refl[i]=i;bool flag;while(1){flag=1;for(int i=1;i<=n;i++){if(Zeller(refl[date[i][0]-'A']*1000+refl[date[i][1]-'A']*100+refl[date[i][2]-'A']*10+refl[date[i][3]-'A'],refl[date[i][4]-'A']*10+refl[date[i][5]-'A'],refl[date[i][6]-'A']*10+refl[date[i][7]-'A'])==0){flag=0;break;}}if(flag==1){printf("Case #%d: ",I);for(int i=0;i<10;i++)printf("%d",refl[i]);printf("\n");break;}else{if(!next_permutation(refl,refl+10))break;}}if(flag==0)printf("Case #%d: Impossible\n",I);}return 0;
}