for _ in range(int(input())):
a, b = list(map(int, input().split()))
s = list(input())
n = len(s)
if ( a%2==1 and b%2==1 ) or ((a%2==1 or b%2==1)and (a+b)%2==0):
print(-1)
continue
stop=0
for i in range(n):
if s[i] == '?':
continue
if s[i] == '1':
if s[n-1-i] == '0':
stop=1
break
if s[i] == '0':
if s[n-1-i] == '1':
stop=1
break
s[n-i-1] = s[i]
if stop:
print(-1)
continue
count_a = count_b = 0
for c in s:
if c=='1':
count_b+=1
elif c=='0':
count_a+=1
if s[n//2 if n%2==1 else n//2-1]=='?':
if a%2==1:
s[n//2 if n%2==1 else n//2-1] = '0'
count_a +=1
elif b%2==1:
s[n//2 if n%2==1 else n//2-1] = '1'
count_b +=1
i=0
j=n-1
while j>=i:
if s[i] == '?':
if count_a < a:
s[i] = s[n-1-i] = '0'
count_a += (1 if n-1-i==i else 2)
elif count_b < b:
s[i] = s[n-1-i] = '1'
count_b += (1 if n-1-i==i else 2)
i+=1
j-=1
print(-1 if count_a!=a or count_b!=b else ''.join(s))#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main()
{
int t;
cin>>t;
while(t--){
int a,b;
cin>>a>>b;
string s;
cin>>s;
int n =s.length();
bool ans = true;
int l = 0;
int r = s.length()-1;
vector<int> ind;
while(l<r){
if(s[l]==s[r] &&s[l]=='?') {
ind.push_back(l);
}
else if(s[l]=='?'){
if(s[r]=='1') b-=2;
else a-=2;
s[l]=s[r];
}
else if(s[r]=='?'){
if(s[l]=='1') b-=2;
else a-=2;
s[r]=s[l];
}
else if(s[l]!=s[r]){
ans =false;
break;
}
else{
if(s[l]=='1') b-=2;
else a-=2;
}
l++;
r--;
}
if(l==r){
if(s[l]=='0') a--;
else if(s[l]=='1') b--;
else{
ind.push_back(l);
}
}
// cout<<a<<" "<<b<<"\n";
// for(auto i : ind) cout<<i<<" ";
// cout<<"\n";
for(int j=0; j<ind.size();j++){
int i = ind[j];
if(i!=(n-1-i)){
if(a>=2){
// cout<<"h"<<" "<<i<<"\n";
a-=2;
s[i]='0';
s[n-1-i]='0';
}
else if(b>=2){
b-=2;
s[i]='1';
s[n-1-i]='1';
}
}
else{
if(a>=1){
a-=1;
s[i]='0';
}
else if(b>=1){
b-=1;
s[i]='1';
}
}
}
if(ans && b==0 && a==0){
for(int i=0; i<s.length(); i++) cout<<s[i];
cout<<"\n";
}
else cout<<-1<<"\n";
}
return 0;
}
1722D - Line | 1722C - Word Game |
1722G - Even-Odd XOR | 552E - Vanya and Brackets |
933A - A Twisty Movement | 1722F - L-shapes |
1196B - Odd Sum Segments | 1325D - Ehab the Xorcist |
552B - Vanya and Books | 1722E - Counting Rectangles |
168A - Wizards and Demonstration | 168B - Wizards and Minimal Spell |
7A - Kalevitch and Chess | 912B - New Year's Eve |
1537C - Challenging Cliffs | 879B - Table Tennis |
1674E - Breaking the Wall | 1282A - Temporarily unavailable |
1366C - Palindromic Paths | 336A - Vasily the Bear and Triangle |
926A - 2-3-numbers | 276D - Little Girl and Maximum XOR |
1253C - Sweets Eating | 1047A - Little C Loves 3 I |
758D - Ability To Convert | 733A - Grasshopper And the String |
216A - Tiling with Hexagons | 1351B - Square |
1225A - Forgetting Things | 1717A - Madoka and Strange Thoughts |