def ip(n):
    '''check if integer n is a prime'''
    # make sure n is a positive integer
    #n = abs(int(n))
    # 0 and 1 are not primes
    if n < 2:
        return False
    # 2 is the only even prime number
    if n == 2: 
        return True    
    # all other even numbers are not primes
    if not n & 1: 
        return False
    # range starts with 3 and only needs to go up the squareroot of n
    # for all odd numbers
    for x in range(3, int(n**0.5)+1, 2):
        if n % x == 0:
            return False
    return True
for _ in xrange(input()):
    s=raw_input().strip()
    d={}
    for c in s:
        if not d.has_key(c):
            d[c]=1
        else:
            d[c]+=1
    l=len(d)
    #print l,d
    if not ip(l):
        print "NO"
    else:
        for k in d:
            if not ip(d[k]):
                print "NO"
                break
        else:
            print "YES"