//#pragma comment(linker, "/STACK:16777216") //for c++ Compiler#include <stdio.h>#include <iostream>#include <fstream>#include <cstring>#include <cmath>#include <stack>#include <string>#include <map>#include <queue>#include <vector>#include <algorithm>#define LL long long#define Max(a,b) (((a) > (b)) ? (a) : (b))#define Min(a,b) (((a) < (b)) ? (a) : (b))#define Abs(x) (((x) > 0) ? (x) : (-(x)))#define MOD 1000000007using namespace std;string Plus(string s1,string s2){     if(s1.length() < s2.length()){          string temp = s1;          s1 = s2;          s2 = temp;     }     for(int i = s1.length() - 1, j = s2.length() - 1; i >= 0; --i, --j){          s1[i] = char(s1[i] + (j >= 0 ? s2[j]- ‘0‘ : 0));          if(s1[i] - ‘0‘ >= 10){              s1[i] = char((s1[i] - ‘0‘) % 10 + ‘0‘);              if(i) ++s1[i-1];              else  s1 += ‘1‘;          }     }     return s1;}string Minus(string a,string b){    string c="",ans="",t;    int flag = 0, k = 0;      bool flag2 = false;     if(a.length() < b.length() || (a.length() == b.length()&& a.compare(b) < 0)){         t = a;        a = b;        b = t;        flag2 = true;    }    int i = a.length() - 1, j = b.length() - 1;    while(i >= 0 && j >= 0){        if(a[i] + flag > b[j]){          c += a[i] + flag - b[j] + ‘0‘;          flag = 0;        }        else if(a[i] + flag == b[j]){          c += ‘0‘;          flag = 0;        }        else{          c += (a[i] - ‘0‘) + flag + 10 - (b[j] - ‘0‘) + ‘0‘;          flag = -1;        }        --i;        --j;        ++k;    }    while(i >= 0){        if(a[i] + flag < ‘0‘){            c += a[i] + flag + 10 + ‘0‘;            flag = -1;        }        else{            c += a[i] + flag;            flag = 0;        }        --i;        ++k;    }    int len = k - 1;    while(c[len] == ‘0‘ && len > 0) --len;    for(j = 0; j <= len; ++j)      ans += c[j];    if(flag2){         ans += ‘-‘;    }    char tt;    for(i = 0, j = ans.length()-1; i < j; ++i, --j){        tt = ans[i];         ans[i] = ans[j];        ans[j] = tt;    }    return ans;}bool judge(string a, string b){    if(a.size() < b.size()) return false;    else if(a.size() > b.size())    return true;    else{        for(int i = 0; i < a.size(); ++i){            if(a[i] > b[i]) return true;            else if(a[i] < b[i]) return false;        }    }}int main(){    int i, j, t, n, m, numCase = 0;    string s1,s2, hh;    string cnt, ans;    bool flag1;    scanf("%d",&t);    while(t--){        cin >> s1 >> s2;        flag1 = false;        int len1 = s1.size();        int len2 = s2.size();        if(judge(s2, s1)){            cout << "Case #" << ++numCase << ": " << Minus(s2, s1) << endl;            continue;        }        for(i = 0; i < len1 - len2; ++i){            string ww = s1.substr(i, len2);            if(ww.compare(s2) == 0){                flag1 = true;                break;            }        }        if(flag1){            cout << "Case #" << ++numCase << ": " << ‘0‘ << endl;            continue;        }        for(i = 0; i < len1 - len2 + 2; ++i){            if(i == len1 - len2 + 1){                hh = s1.substr(len1 - len2 - i + 1, i + len2 - 1);            } else{                hh = s1.substr(len1 - len2 - i, i + len2);            }            if(judge(hh, s2)){                string gg = "1";                gg += s2;                ans = Minus(gg ,hh);            }            else{                ans = Minus(s2 ,hh);            }            s2 += "0";            if(i == 0){                cnt = ans;            } else{                if(judge(cnt, ans)){                    cnt = ans;                }            }        }        cout << "Case #" << ++numCase << ": " << cnt << endl;    }    return 0;}