n= int( input() ) 
q=n//1000
b=n//100%10
s=n//10%10
g=n%10
if q==g and b==s:
    print('yes')
else:
    print('no')

/**************************************************************
	Problem: 1647
	User: admin
	Language: Python
	Result: Accepted
	Time:113 ms
	Memory:34244 kb
****************************************************************/