Go: package main

import (
	"bufio"
	"io"
	"os"
	"strconv"
	"fmt"
)

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()
	n := nint()
	r := fibonacci(n)
	fmt.Println(r)
}

func fibonacci(n int) int{
	if n == 0 || n == 1{
		return 1
	}else{
		fiList := make([]int, n+1)
		fiList[0] = 1
		fiList[1] = 1
		for i:=2; i<n+1; i++{
			fiList[i] = fiList[i-1] + fiList[i-2]
		}
		return fiList[n]

	}

}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

Python: n = int(input())

def fib(i):
    if i<=1:
        return 1
    
    else:
        a, b = 0, 1
        for i in range(n+1):
            c = b + a
            b = a
            a = c
        return c

print(fib(n))

Python: target = int(input()) + 1
fib = [0 for n in range(target + 1)]
for i in range(target + 1):
    if i == 0:
        continue
    elif i == 1:
        fib[i] = 1
    else:
        fib[i] = fib[i - 1] + fib[i - 2]
print(fib[target])

Python: # ???????¨?????????????????§£???
# ?????°?????¨?????¢??????????????¨???????????¢????????£???


def fibonacci(n):
    num1 = 1
    num2 = 1
    tmp = 1

    for i in range(1, n):
        tmp = num1 + num2
        num1 = num2
        num2 = tmp

    return tmp


if __name__ == '__main__':
    n = int(input())
    result = fibonacci(n)
    print(result)

Python: #フィボナッチ数列
n = int(input())
dp = [0 for i in range(1000)]
dp[0] = 1
dp[1] = 1
for i in range(2,n+1):
    dp[i] = dp[i-1] + dp[i -2]
    
print(dp[n])

Python: n=int(input())

fib=[1,1]
for i in range(2,n+1):
    a=fib[i-1]+fib[i-2]
    fib.append(a)

print(fib[n])

Python: F = [1,1]
for i in range(2, int(input())+1):
    F.append(F[i-2] + F[i-1])
print(F[-1])

Python: dp = [0]*50

def fib(n):
    if dp[n] != 0:
        return dp[n]
    if n==0:
        dp[n] = 1
    elif n==1:
        dp[n] = 1
    else:
        dp[n] = fib(n-1)+fib(n-2)
    return dp[n]

print(fib(int(input())))

Python: class Fibonacci(object):
    record = [1, 1]
    
    def get_nth(self, n):
        if n < len(Fibonacci.record):
            return Fibonacci.record[n]
        
        for i in range(len(Fibonacci.record), n+1):
            result = Fibonacci.record[i-1] + Fibonacci.record[i-2]
            Fibonacci.record.append(result)
        
        return Fibonacci.record[n]
 
 
if __name__ == '__main__':
    num = int(input())
    f = Fibonacci()
    result = f.get_nth(num)
    print('{0}'.format(result))

Python: n = int(input())

fibs = [0 for _ in range(n+1)]
# checks = [False for _ in range(n+1)]

def fib(k):
    for i in range(k+1):
        if i == 0:
            fibs[i] = 1
        elif i == 1:
            fibs[i] = 1
        else:
            fibs[i] = fibs[i-1] + fibs[i-2]
    return fibs[k]

print(fib(n))

Python: from functools import lru_cache


@lru_cache(maxsize=None)
def fib(n):
    """ http://docs.python.jp/3/library/functools.html """
    if n < 2:
        return n
    return fib(n-1) + fib(n-2)


class Fibonacci(object):
    memo = [1, 1]

    def get_nth(self, n):
        if n < len(Fibonacci.memo):
            return Fibonacci.memo[n]
        # print('fib({0}) not found'.format(n))
        for i in range(len(Fibonacci.memo), n+1):
            result = Fibonacci.memo[i-1] + Fibonacci.memo[i-2]
            Fibonacci.memo.append(result)
            # print('fib({0})={1} append'.format(i, result))
        return Fibonacci.memo[n]


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())

    # ?????£??????????????°????¨????
    # f = Fibonacci()
    # result = f.get_nth(num)
    result = fib(num+1)

    # ???????????????
    print('{0}'.format(result))

Python: f=[1,1]
for _ in[0]*43:f+=[f(-2)+f(-1)]
print(f[int(input())])

Python: n = int(input())

def fib(n):
    Fib = [1,1]
    if n == 0 or n == 1:
        return Fib[n]
    for i in range(2,n+1):
        Fib.append(Fib[i-1] + Fib[i-2])
    return Fib[n]

print(fib(n))

Python: import sys
import itertools
sys.setrecursionlimit(1000000000)
from heapq import heapify,heappop,heappush,heappushpop
import math
import collections
import copy

n = int(input())
dp = [0]*(1000001)
dp[0] = 1
dp[1] = 1
for i in range(2,n+1):
    dp[i] = dp[i-1] + dp[i-2]
print(dp[n])

Python: _fib = [None] * 44
_fib[0] = 1
_fib[1] = 1

def fib(n):
    if _fib[n] is None:
        _fib[n] = fib(n-1) + fib(n-2)
    return _fib[n]

_n = int(raw_input())
print(fib(_n))

Python: _fib = [1, 1]

def fib(n):
    if len(_fib) > n:
        return _fib[n]
    else:
        _fib[n] = fib(n-1) + fib(n-2)
        return _fib[n]

_n = int(raw_input())
print(fib(_n))

Python: n = int(input())
dp = {}
def fibonacci(n):
    if n == 0 or n == 1:
        return 1
    if n in dp:
        return dp[n]
    dp[n] = fibonacci(n-1) + fibonacci(n-2)
    return dp[n]
print(fibonacci(n))

Python: n=int(input())
if n == 1:
    print(1)
elif n == 2:
    print(2)
else:
    p=n+1 
    a=((1+5**(1/2))/2)**p
    b=((1-5**(1/2))/2)**p
    c=1/(5**(1/2))
    print(int(c*(a-b)))

Python: a = int(input())

memo = [0]*100000

def  fib(n):

    if n == 0 or n ==  1:
        memo[n] =1

    if memo[n] == 0:
        memo[n] = fib(n-2) + fib(n-1)
        return memo[n]
    else:
        return memo[n]



print(fib(a))

Python: N=int(input())
L=[0 for i in range(N+1)]
L[0]=1
L[1]=1
for i in range(2,N+1):
    L[i]=L[i-1]+L[i-2]
print(L[N])

Python: N = int(input())
dp = [0] * (N+1)
dp[0] = 1
dp[1] = 1
for i in range(2,N+1):
    dp[i] = dp[i-1] + dp[i-2]

print(dp[N])

Python: n = int(input())
f = [1,1]
for i in range(n-1):
    fib = f[-1] + f[-2]
    f.append(fib)
print(f[n])

Python: fib=[0]*45
fib[0]=1
fib[1]=1

n=int(input())

for i in range(2,45):
    fib[i]=fib[i-1]+fib[i-2]
    
    
print(fib[n])

Python: n = int(input())
dp = [1, 1]
if n >1:
  for i in range(2, n + 1):
    dp.append(dp[i - 1] + dp[i - 2])
print(dp[n])

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys


def fib_bad(n):
    if not n or n == 1:
        return 1
    return fib_bad(n - 2) + fib_bad(n - 1)


def fib_dp(n):
    fib_list[:1] = [1, 1]
    for i in range(2, n + 1):
        fib_list[i] = fib_list[i - 2] + fib_list[i - 1]
    return fib_list.pop()


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    index = int(_input[0])
    fib_list = [None] * index
    # print(fib_bad(index))
    print(fib_dp(index))