Go: package main

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

// func fib(n int) int{
// 	if n == 0 || n == 1{
// 		return 1
// 	} else {
// 		return fib(n-1) + fib(n-2)
// 	}
// }

// func main(){
// 	sc := bufio.NewScanner(os.Stdin)
// 	sc.Scan()
// 	n, _ := strconv.Atoi(sc.Text())
// 	fmt.Println(fib(n))
// }

import (
	"fmt"
)

func main(){
	var n, pre1, pre2, now int
	fmt.Scan(&n)
	if n == 0 || n == 1{
		fmt.Println(1)
	} else {
		pre1, pre2 = 1, 1
		for i:=1; i<n; i++{
			now = pre1 + pre2
			pre2 = pre1
			pre1 = now
		}
		fmt.Println(now)
	}

}

Python: def fib(n, memo={}):
    if n == 0:
        return 1
    elif n == 1:
        return 1
    elif n in memo:
        return memo[n]
    else:
        memo[n] = fib(n-1, memo)+fib(n-2, memo)
        return memo[n]


def main():
    n = int(input())
    print(fib(n))


if __name__ == '__main__':
    main()

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

Python: def memoize(f):  
    cache = {}  
    def helper(x):  
        if x not in cache:              
            cache[x] = f(x)  
        return cache[x]  
    return helper 
         
@memoize
def fib(n):
    if n in (0, 1):
        return 1
    else:
        return fib(n - 1) + fib(n - 2)
 
print(fib(int(input())))

Python: def fib(n):
    if n==0 or n==1:
        return 1
    else:
        return fib(n-1) + fib(n-2)
print(fib(int(input())))

Python: memo = {}


def f(n):
    if n == 0:
        return 1
    if n == 1:
        return 1

    a1 = memo.get(n - 1)
    if not a1:
        a1 = f(n - 1)
        memo[n - 1] = a1

    a2 = memo.get(n - 2)
    if not a2:
        a2 = f(n - 2)
        memo[n - 2] = a2

    return a1 + a2


n = int(input())
print(f(n))

Python: import sys
import math
import fractions
import itertools
from collections import deque
import copy
import bisect

MOD = 10 ** 9 + 7
INF = 10 ** 18 + 7
input = lambda: sys.stdin.readline().strip()

fib_list = [-1 for _ in range(100)]


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


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

Python: n = int(input())

dp = [0 for _ in range(45)]
dp[0], dp[1] = 1, 1


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

print(dp[n])

Python: def fib(n):
  if n < 0:
    print("error")
    exit()
  if n < 2:
    return 1
  result = fib(n-1) + fib(n-2)
  return result

n = int(input())
print(fib(n))

Python: def fibonacci(i, num_list):
    if i == 0 or i == 1:
        num_list[i] = 1
    else:
        num_list[i] = num_list[i-2] + num_list[i-1]

n = int(input()) + 1
num_list = [0 for i in range(n)]
for i in range(n):
    fibonacci(i, num_list)
print(num_list[-1])

Python: n = int(input())

fib = []
ans = 0
for i in range(n+1):
    if i == 0 or i == 1:
        ans = 1
        fib.append(ans)
    else:
        ans = fib[i-1] + fib[i-2]
        fib.append(ans)

print(ans)

Python: n = int(input())
p = [1,1]

if n <= 1:
    print (1)
    exit (0)

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

print (p[n])

Python: n = int(input())

num = [-1] * 100


def fibonacci(n):
    if n == 0:
        num[0] = 1
    elif n == 1:
        num[1] = 1

    if num[n] == -1:
        num[n] = fibonacci(n - 1) + fibonacci(n - 2)

    return num[n]


print(fibonacci(n))

Python: l = [0 for i in range(45)]
l[0] = 1
l[1] = 1
def F(n):
    if l[n] != 0:
        return l[n]
    else:
        l[n] = F(n-1) + F(n-2)
        return l[n]
print(F(int(input())))

Python: num = int(input())

dp = { 0: 1, 1: 1 }
def fibonacci(n):
  if not n in dp:
    dp[n] = fibonacci(n - 1) + fibonacci(n - 2)
  return dp[n]

print(fibonacci(num))