

def main():
    n = int(input())
    dp = [0] * 100
    dp[0] = 1
    dp[1] = 1
    for i in range(2, len(dp)):
        dp[i] = dp[i - 1] + dp[i - 2]
    print(dp[n])


if __name__ == '__main__':
    main() def main():
    n = int(input())
    dp = [0] * 100
    dp[0] = 1
    dp[1] = 1
    for i in range(2, len(dp)):
        dp[i] = dp[i - 1] + dp[i - 2]
    print(dp[n]) main n = int(input()) n int(input()) int input() input dp = [0] * 100 dp [0] * 100 [0] 0 100 dp[0] = 1 dp[0] dp 0 1 dp[1] = 1 dp[1] dp 1 1 for i in range(2, len(dp)):
        dp[i] = dp[i - 1] + dp[i - 2]
     i range(2, len(dp)) range 2 len(dp) len dp dp[i] = dp[i - 1] + dp[i - 2] dp[i] dp i dp[i - 1] + dp[i - 2] dp[i - 1] dp i - 1 i 1 dp[i - 2] dp i - 2 i 2 print(dp[n]) print dp[n] dp n if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():
    n = int(input())
    dp = [0] * 100
    dp[0] = 1
    dp[1] = 1
    for i in range(2, len(dp)):
        dp[i] = dp[i - 1] + dp[i - 2]
    print(dp[n]) def main():
    n = int(input())
    dp = [0] * 100
    dp[0] = 1
    dp[1] = 1
    for i in range(2, len(dp)):
        dp[i] = dp[i - 1] + dp[i - 2]
    print(dp[n]) main


def main():
    n = int(input())
    dp = [0] * 100
    dp[0] = 1
    dp[1] = 1
    for i in range(2, len(dp)):
        dp[i] = dp[i - 1] + dp[i - 2]
    print(dp[n])


if __name__ == '__main__':
    main()