1 #include<iostream>
2
3 using namespace std;
4
5 const int maxn =100+10;
6
7 char s[maxn],t[maxn];
8
9 int main(){
10 //freopen("10.in", "r", stdin);
11 //freopen("10.out", "w", stdout);
12 int n;
13 cin >> n;
14 for(int i = 1; i <= n; i ++){
15 cin >> s >> t;
16 cout << "Case " << i << ": ";
17 int s1 = 0, t1 = 0, q1 = 0, num = 0;
18 int len = strlen(s);
19 for(int j = 0; j < len; j ++){
20 if(t[j] == '0') t1 ++;
21 if(s[j] == '0') s1 ++;
22 if(s[j] == '?'){
23 q1 ++;
24 num ++;
25 }
26 if(s[j] == '?' && t[j] == '0'){
27 s[j] = '0';
28 s1 ++;
29 q1 --;
30 }
31 }
32 if(s1 + q1 < t1){
33 cout << "-1" << endl;
34 continue;
35 }
36 int sum = t1 - s1;
37 int s0 = 0, s2 = 0;
38 for(int k = 0; k < len; k ++){
39 if(s[k] == '0' && t[k] == '1') s0++;
40 }
41 if(sum > 0){
42 s0 += sum;
43 }
44 num += s0;
45 cout << num << endl;
46 }
47 return 0;
48 }
