s = int(input())
s +=1
s = list(map(int,list(str(s))))
for i in range(10000):
for i in range(0,len(s)//2+1):
if s[i] < s[len(s)-i-1]:
s[len(s)-i-2] += 1
s[len(s)-i-1] = s[i]
for i in range(len(s)-1,-1,-1):
if s[i] >=10:
s[i],s[i-1] = s[i]%10,s[i-1]+s[i]//10
for i in s:
print(i,end="")