# Write a program that takes in a string representing an integer as input, and outputs yes 
# if every character is a digit 0-9 or No otherwise 

# if the input is: 
# 1995 

# the output is: 
# Yes 

#if the input is: 
# 42,000

#or any string with a non-integer character, the output is: 

#  No 


user_string = input()

if user_string.isdigit():
    print("Yes")

else: 
    print("No")