def main():
    subset_judge()

def subset_judge():
    x = input()
    x = x.split()
    a = x[0]
    b = x[-1]
    count = 0
    for n in range(len(b)):
        if a[-1 + -n] < b[-1 + -n]:
            print('No')
            break
        count += 1
        if count == len(b):
            print('Yes')
    
if __name__ == '__main__':
    main()