1948A - Special Characters - CodeForces Solution

T = int(input())

while T > 0:
    n = int(input())
    if n % 2 == 1:
        print("NO")
    else:
        print("YES")
        c1 = 'AA'
        c2 = 'BB'
        ans = ''
        for i in range(n // 2):
            if i % 2 == 0:
                ans += c1
            else:
                ans += c2
        print(ans)
    
    T-=1