Codechef_3

t=int(input(''))
for i in range(t):
    x=int(input(''))
    a=input('')
    w=[]
    for i in range(0,x-2):
        for j in range(i,x+1):
            w.append(a[i:j])
    for i in w:
        q=0
        for j in i:
            if j=='L':
                q+=1
            else:
                q-=1
        if abs(q)%2==0 and q!=0:
            print('YES')
            break
        else:
            pass
    else:
        print('NO')