I could pass them all use the following. I have a helper function called fast_get that one will return '[' which is the next ascii charecter after Z in case any of the stacks reached end of index. This way I can make sure even if I get out of bond ot the stacks the loop still works fine.

`python def fast_get(seq, i, default='['): return seq[i] if 0 <= i < len(seq) else default

def morganAndString(a, b): # Write your code here a = deque(a) b= deque(b) result="" while a or b: if a and b: i=0

        while fast_get(a,i)==fast_get(b,i) and (i<len(a) or i< len(b)):
            i+=1
            if fast_get(a,i)<fast_get(b,i):
                for _ in range(i+1):
                    result+= a.popleft()
                i=0


            elif fast_get(b,i)<fast_get(a,i):
                for _ in range(i+1):
                    result+= b.popleft()
                i=0
        i=0                            
        if fast_get(a,i)<fast_get(b,i):
            result += a.popleft()


        elif fast_get(b,i)<fast_get(a,i):
            result += b.popleft()
        elif fast_get(b,i)==fast_get(a,i):
            result += a.popleft()                

    elif b:
        result += b.popleft()
    elif a:
        result += a.popleft()
return result
```