q = int(input())
A = []
n = 0
for i in range(q):
    n = int(input())
    S = input()
    A.append((n, S))
for i in A:
    if i[0] % 2 == 1:
        res = [i[1][:i[0]//2], i[1][i[0]//2:]]
    elif i[0] != 2:
        res = [i[1][0],i[1][1:]]
    else:
        print('NO')
        break
    print('YES')
    print(len(res))
    print(*res)