mod = False

def mult(A, B):
    Ret = []
    Ret.append(A[0] * B[0] + A[1] * B[2])
    Ret.append(A[0] * B[1] + A[1] * B[3])
    Ret.append(A[2] * B[0] + A[3] * B[2])
    Ret.append(A[2] * B[1] + A[3] * B[3])
    if mod:
        for i in range(len(Ret)):
            Ret[i] = Ret[i] % 10**100
    return Ret

try:
    while True:
        n = int(input())
        k = 1
        pow_ = 2
        DP = []
        DP.append([1, 1, 1, 0])
        while pow_ <= n:
            DP.append(mult(DP[k - 1], DP[k - 1]))
            pow_ *= 2
            k += 1
        Out = [1, 0, 0, 1]
        while n > 0:
            if n >= pow_:
                n -= pow_
                Out = mult(DP[k], Out)
            pow_ //= 2;
            k -= 1
        print (Out[1])

except EOFError:
    pass