模拟

n = int(input())def check(x):m = int(x[:2])d = int(x[2:4])x = int(x)if 1<=m<=12:if m == 2:if (x%4==0 and x%100!=0) or x%400==0:if d<=29:return Trueelse:return Falseelse: if d<=28:return Trueelse:return Falseif m in [1,3,5,7,8,10,12]:if d<=31:return Trueelse:return Falseelse:if d<=30:return Truereturn Falsereturn False
arr1 = []
arr2 = []
for i in range(1000, 9999):x1 = str(i)[::-1]x2 = (str(i)[:2]+str(i)[:2])[::-1]if check(x1) and int(x1[::-1]+x1)>n:arr1.append(int(x1[::-1]+x1))if check(x2) and int(x2[::-1]+x2)>n:arr2.append(int(x2[::-1]+x2))print(arr1[0])
print(arr2[0])