1
2 2
1 1
1 2
 1
1 3
3
1 2 3
 1
1 1
1000
1000
 1
2 2
2 2
2 2
 5
4 5
10 8 6 4
1 2 3 4 5
1 1
3
3
1 1
3
2
5 3
1000 2 2 2 3
3 1 5
5 5
1 2 3 4 5
1 2 3 4 5
 1
4 4
1 1 1 1
1 2 3 4
 1
2 3
1 1
1 2 3

YES
1 1
 YES
1 3
 YES
1 1000
 YES
1 2
 YES
1 4
YES
1 3
NO
YES
1 3
YES
1 1
 YES
1 1
 YES
1 1

t=int(input())
for i in range(t):
    stri=''
    m,n=list(map(int,input().split()))
    l1=list(map(int,input().split()))[:m]
    l2=list(map(int,input().split()))[:n]
    c=0
    for i in l1:
        for j in l2:
            if i==j:
                c+=1
                x=str(i)
                stri=stri+x
                
    if c==m==n==1:
        stri=str(l1[0])
    if c==m==n and c>1:
        c=1
        stri=str(l1[0])
        
    

    if c>0:
        print("YES")
        print(c,''.join(stri))
    else:
        print("NO")
    
    