B"In the 2022 year, Mike found two binary integers a and b of length n (both of them are written only by digits 0 and 1 ) that can have leading zeroes. In order not to forget them, he wanted to construct integer d in the following way: Unfortunately, Mike lost integer a before he could calculate d himself. Now, to cheer him up, you want to find any binary integer a of length n such that d will be maximum possible as integer. Maximum possible as integer means that 102 > 21 , 012 < 101 , 021 = 21 and so on. The first line contains a single integer t ( 1 <= q t <= q 1000 ) -- the number of test cases. The first line of each test case contains the integer n ( 1 <= q n <= q 10^5 ) -- the length of a and b . The second line of each test case contains binary integer b of length n . The integer b consists only of digits 0 and 1 . It is guaranteed that the total sum of n over all t test cases doesn't exceed 10^5 . For each test case output one binary integer a of length n . Note, that a or b may have leading zeroes but must have the same length n . In the first test case, b = 0 and choosing a = 1 gives d = 1 as a result. In the second test case, b = 011 so: In the third test case, b = 110 . If you choose a = 100 , you'll get d = 210 and it's the maximum possible d . In the fourth test case, b = 111000 . If you choose a = 101101 , you'll get d = 212101 and it's maximum possible d . In the fifth test case, b = 001011 . If you choose a = 101110 , you'll get d = 102121 and it's maximum possible d . "...