from math import sqrt

def main():
    last = 0
    limit = 100000
    strike = [False for i in range(limit)]
    for i in range(2, int(sqrt(limit))):
        if not strike[i]:
            last = i
        for i in range(i**2, limit, i):
            strike[i] = True
    print([i for i in range(int(sqrt(limit)) + 1, limit) if not strike[i]][-1])


if __name__ == '__main__':
    main()