def replace(A,B):
    reverse = []
    for i in B:
        for j  in A:
            if i == j:
                reverse.append(j)
                break
    if ''.join(reverse) == ''.join(B):
        return "YES"
    else:
        return "NO"

A = list(input())
B = list(input())

print(replace(A,B))