# Uses python3
n = int(input())
def FibFast(n):
    k = [0, 1]
    for i in range (2, n+1):
        k.append(k[-1] + k[-2])
    if n == 0:
        return 0
    else: 
        return k[-1]
print(FibFast(n))
8c2f141df90ae0abd467a875e76a22ece354affb
<mask token>

<mask token>


def FibFast(n):
    k = [0, 1]
    for i in range(2, n + 1):
        k.append(k[-1] + k[-2])
    if n == 0:
        return 0
    else:
        return k[-1]


<mask token>

<mask token>


def FibFast(n):
    k = [0, 1]
    for i in range(2, n + 1):
        k.append(k[-1] + k[-2])
    if n == 0:
        return 0
    else:
        return k[-1]


print(FibFast(n))

n = int(input())


def FibFast(n):
    k = [0, 1]
    for i in range(2, n + 1):
        k.append(k[-1] + k[-2])
    if n == 0:
        return 0
    else:
        return k[-1]


print(FibFast(n))

# Uses python3
n = int(input())
def FibFast(n):
    k = [0, 1]
    for i in range (2, n+1):
        k.append(k[-1] + k[-2])
    if n == 0:
        return 0
    else: 
        return k[-1]
print(FibFast(n))