try:
    import mydebug

    def dprint(*objects, sep='', end='\n'):
        print(*objects)
except:
    def dprint(*objects, sep='', end='\n'): pass

n = int(input())

for i in range(n - 100, n + 100 + 1):
    if i in (1, 2, 3):
        continue
    for j in range(2, i + 1):
        if i % j == 0 and j != i:
            print(i)
            import sys
            sys.exit()