Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	dp := make([]int, N+1)
	dp[0] = 1
	dp[1] = 1
	for i := 2; i <= N; i++ {
		dp[i] = dp[i-1] + dp[i-2]
	}

	fmt.Fprintln(wtr, dp[N])
	wtr.Flush()
}

C++: #include <stdio.h>

int main() {
    int n;
    scanf("%d", &n);
    int F[50];
    F[0] = 1;
    F[1] = 1;
    for(int i=2; i<50; i++) F[i] = F[i-2] + F[i];
    
    printf("%d\n", F[n]);
    return 0;
}

C++: #include <iostream>

int main()
{
	int n; std::cin >> n;
	
	long long int* DP = new long long int[n+1];
	DP[0] = DP[1] = 1;
	for (int i=2; i<=n; i++) DP[i] = DP[i-1] + DP[i-2];
	
	std::cout << DP[n] << std::endl;
	
	delete[] DP;
	
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int main(){
    int f[45],n;
    cin>>n;
    f[0]=1;f[1]=1;
    for(int i=2;i<45;i++){
        f[i]=f[i-1]+f[i-2];
    }
    cout<<f[n]<<endl;
    return 0;
}

C++: #include <algorithm>
#include <cassert>
#include <climits>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <string>
#include <vector>

#define all(x) begin(x), end(x)

using namespace std;

template <typename T> T gcd(T a, T b) {
  if (a % b == 0) {
    return b;
  } else {
    return gcd(b, a % b);
  }
}

template <typename T> T lcm(T a, T b) { return a * b / gcd(a, b); }

int dp[45] = {0};
int fib(int n) {
    if (n == 0 || n == 1) {
        return 1;
    }
    if (dp[n-1] != 0) {
        if (dp[n-2] != 0) {
            return dp[n-1] + dp[n-2];
        }
    }
    dp[n-1] = fib(n-1);
    dp[n-2] = fib(n-2);
    return dp[n-1] + dp[n-2];
}

int main() {
  int n;
  cin >> n;
  cout << fib(n) << endl;
}

C++: /*
    ????????°??§???????????¨????????????
*/

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <limits.h>
#include <float.h>
#include <iostream>
#include <algorithm>
#include <string>
#include <iterator>
#include <vector>
#include <map>
#include <utility>
#define LLU unsigned long long int
#define LL long long int
#define LD long double
using namespace std;
#define Lfmax DBL_MAX
#define LLUmax ULLONG_MAX
#define LLmax LLONG_MAX
#define dmax INT_MAX
#define vd vector<int>
#define vLL vector<long long int>
#define vLLU vector<unsigned long long int> 
#define pb push_back
#define mp make_pair
#define fi first
#define sec second
#define debug printf("asd\n")
#define debugd(a) printf("--%d\n",a)
#define debugdd(a,b) printf("--%d %d\n",a,b)
#define debugarr(a,b) for(int i=0 ; i<b ; i++)printf("%d ",a[i]);printf("\n")
#define newline printf("\n")
#define forin(a,b,c) for(int a=b ; a<c ; a++)
#define forde(a,b,c) for(int a=b ; a>=c ; a--)


inline void scd(int &a){scanf("%d",&a);}
inline void scdd(int &a,int &b){scanf("%d %d",&a,&b);}
inline void sctd(int &a,int &b,int &c){scanf("%d %d %d",&a,&b,&c);}
inline void scdlld(LL &a,LL &b){scanf("%I64d %I64d",&a,&b);}
inline void sclld(LL &a){scanf("%I64d",&a);}

#define scarrd(a,b) for(int index=0 ; index<b ; index++)scanf("%d",&a[index])
#define prdlld(a,b) printf("%I64d %I64d",a,b)
#define prdd(a,b) printf("%d %d",a,b)
#define prd(a) printf("%d",a)
#define prarr(a,b) for(int i=0 ; i<b ; i++)printf("%d ",a[i])
#define iniarr(a,b) for(int i=0 ; i<b ;i++)a[i]=0
#define arr(a,b) int *a=(int *)malloc(b*sizeof(int))
#define llarr(a,b) long long int *a=(long long int *)malloc(b*sizeof(long long int))
#define st(a,b) char *a=(char *)malloc(b*sizeof(char))
#define grav 9.8
#define pi 3.14159265

int fbc[200000];

int fb(int a)
{
	if(fbc[a]>0)
	return fbc[a];
	
	
	if(a<2)
	return 1;
	
	fbc[a]=fb(a-1)+fb(a-2);
	return fbc[a];
	
}

int main()
{
	iniarr(fbc,200000);
	int a;
	scd(a);
	printf("%d\n",fb(a));	
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int main(){
    vector<int> dp;
    dp.push_back(1),dp.push_back(1);
    for(int i=0;i<44;i++)dp.push_back(dp[i]+dp[i+1]);
    int N;scanf("%d",&N);
    printf("%d\n",dp[N]);
    return 0;
}

C++: #include <bits/stdc++.h>
#define int long long
typedef long long ll;
using namespace std;

ll N, M, score=0;
vector<ll> Fib;

void dp(){
    for(int i=2;i<=N;i++) Fib[i] = Fib[i-1]+Fib[i-2];
}

signed main(){
    cin >> N;
    Fib.resize(N+1);
    Fib[0]=1;
    Fib[1]=1; 
    dp();
    cout << Fib[N] << endl;
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define _GLIBCXX_DEBUG
const int INF_INT = 2147483647;
const long long INF_LONG = 9223372036854775807;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
     
int main() {
  int n;  cin >> n;

  vector<ll> v(100);
  v[0] = 1;
  v[1] = 1;

  for (int i=2; i<=n; ++i) {
    v[i] = v[i-1] + v[i-2];
  }

  cout << v[n] << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, n) for(int i = 0; i < n; i++)
#define all(a) a.begin(), a.end()
#define P pair<int, int>
#define F first
#define S second
#define prime 1000000007
#define INF 40000000000000000
int dx8[8] = {-1, 0, 1, 1, 1, 0, -1, -1};
int dy8[8] = {1, 1, 1, 0, -1, -1, -1, 0};
int dx4[4] = {-1, 0, 1, 0};
int dy4[4] = {0, -1, 0, 1};
signed main(void) {
    int fib[48];
    fib[0] = 1;
    fib[1] = 1;
    rep(i, 45) fib[i + 2] = fib[i + 1] + fib[i];
    int n;
    cin >> n;
    cout << fib[n] << endl;
}

C++: // fibonacci
#include<iostream>
#define MAX 50
long f(long);
long F[MAX],n;
int main(){
  long i;
  std::cin >> n;
  for(i=0; i<MAX; i++) F[i] = -1;
  std::cout << f(n) << "\n";
  return 0;
}
long f(long n){
  if(n == 1 || n == 0) return F[n] = 1;
  if(F[n] != -1) return F[n];
  return F[n] = f(n - 2) + f(n - 1);
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (int)(n); i++)


int main() {
  int n;
  cin >> n;
  vector<int> fibo(n);
  
  for(int i = 0;i < n;i++){
      if(i == 0){
          fibo.at(i) = 1;
      }else if(i == 1){
          fibo.at(i) = 2;
      }else{
          fibo.at(i) = fibo.at(i-1)+fibo.at(i-2);
      }
  }
  cout << fibo.at(n-1) << endl;
  
}