Go: package main

/*
フィボナッチ数列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func fibWithMemo(n int, memo map[int]int) int {
	if n == 0 || n == 1 {
		return 1
	}
	if val, ok := memo[n]; ok {
		return val
	}
	memo[n] = fibWithMemo(n-1, memo) + fibWithMemo(n-2, memo)
	return memo[n]
}

func fib(n int) int {
	memo := make(map[int]int)
	return fibWithMemo(n, memo)
}

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	fmt.Println(fib(n))
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: #include <iostream>
#include <vector>
using namespace std;

int main() {
   int N; cin >> N;
   vector<int>F(50);
   F[0] = F[1] = 1;
   for (int i = 2; i <= N; i++) F[i] = F[i - 1] + F[i - 2];
   
   cout << F.at(N) << endl;
}

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

using ll = long long;

int main() {
    int n;
    cin >> n;
    vector<ll> f(n + 1, 1);
    rep(i, n - 1) f[i + 2] = f[i] + f[i + 1];
    cout << f[n] << "\n";
}

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

typedef vector<vector<ll> > mat;

//行列累乗
// mat は vector<vectorのこと

// A*B　の　計算
mat mul( mat &A, mat &B){
 mat  C(A.size(), vector<ll>(B[0].size()));
 for(ll i = 0; i < A.size(); i++){
   for(ll k = 0; k < B.size(); k++){
     for(ll j = 0; j < B[0].size();j++){
       C[i][j] = (C[i][j]+A[i][k]*B[k][j]);
     }
   }
 }
return C;
}

// A^nの計算

mat pow(mat A, ll n){
  mat B(A.size(), vector<ll>(A.size()));
  
  for(int i = 0; i < A.size(); i++){
    B[i][i] = 1;}
 
  while( n > 0){
    if( n & 1){  
      B = mul(B,A);}
      A = mul(A,A);
      n >>= 1;
    }
    
    return B;
  }
  
  ll N;
  
int main(){
  cin >> N;
 
  mat A(2,vector<ll>(2));
  A[0][0] = 1LL; A[0][1] = 1LL; A[1][0] = 1LL; A[1][1] = 0LL;
  cout << pow(A,N+1)[1][0] << endl; return 0;}

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

int main()
{
  int n;
  cin >> n;
  int dp[n+1];
  dp[0] = 1;
  dp[1] = 1;
  for(int i=2;i <= n;i++){
      dp[i] = dp[i-1]+dp[i-2];
  }
  
  printf("%d\n",dp[n]);
  return 0;
}

C++: #include <iostream>
#include <stdio.h>
using namespace std;

int main()
{
	int n,x1=1,x2=1,tmp;
	cin >> n;
	
	if(n==0||n==1) cout << "1";
	else{
		for(;n>2;n--){
			tmp=x1+x2;
			x1=x2;
			x2=tmp;
		}
		cout << x1 + x2 << endl;
	}
	
	return 0;
	
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <stdlib.h>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
int f[45];
int fib(int n){
  if(n==1||n==0)return 1;
  if(f[n]!=0)return f[n];
  else return fib(n-1)+fib(n-2);
}
int main(){
  int  n;
  cin>>n;
  cout<<fib(n)<<endl;



  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
main(){
  int a[44],n;
  a[0]=a[1]=1;
  cin>>n;
  for(int i=2;i<=n;i++)a[i]=a[i-1]+a[i-2];
  cout<<a[n]<<endl; 
}

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


int main()
{
    int n;
    cin >> n;
    int f1 = 1, f2 = 1;
    int temp;
    if(n == 0 && n == 1){
        cout << 1 << endl;
        return 0;
    }
    for(int i = 0; i < n - 1; i++){
        temp = f2;
        f2 = f1 + f2;
        f1 = temp;
    }
    cout << f2 << endl;
    
    return 0;
}

C++: #include<iostream>

using namespace std;

int main(){

  int n;

  int n1,n2,st;
  //initialize
  n1=1;
  n2=1;
  st=1;
  //load number
  cin >>n;
  //fibonacci
  for(int i=1;i<n;i++){
    st=n1+n2;
    n1=n2;
    n2=st;
  }
  //print
  cout <<st<<endl;
  return 0;
}

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

int main() {
    int n; cin >> n;
    long long a = 0, b = 1;
    while (n--) {
        long long c = a + b;
        a = b;
        b = c;
    }
    cout << b << endl;
}

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

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n; cin >> n;
  vector<int> dp(n+1,1);
  for(int i = 2; i <= n; i++){
    dp[i] = dp[i-1] + dp[i-2];
  }
  cout << dp[n] << endl;

  return 0;
}

C++: #include<iostream>
using namespace std;

int fib(int n){
  switch(n){
  case 0:
    return 1;
  case 1:
    return 1;
  default:
    return fib(n-1) + fib(n-2);
  }
}

int main(){
  int n;
  cin>>n;
  cout<<fib(n)<<endl;
  return 0;
}

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

int fib[50];

int main() {
    int n; cin >> n;
    fib[0] = fib[1] = 1;
    for (int i = 2; i < 50; ++i) {
        fib[i] = fib[i-1]+fib[i-2];
    }
    cout << fib[n] << endl;
}

C++: #include <iostream>
#include <cstdio>

using namespace std;

long long fib[45];

int main(void) {

    fib[0] = fib[1] = 1;
    for (int i = 2; i < 45; ++i) {
        fib[i] = fib[i - 1] + fib[i - 2];
    }

    int n;
    cin >> n;
    printf("%lld\n", fib[n]);

    return 0;
}

C++: #include<iostream>

using namespace std;
int fib(int n);
int main() {
  int n;

  //入力
  cin >> n;

  //出力
  cout << fib(n) << endl;

  return 0;
}

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

C++: #include <stdio.h>
#include <stdlib.h>
#define N 45
 
int f[N];
int fib(int);

int main(){
  int n,i;
  
  scanf("%d",&n);
  printf("%d\n",fib(n));
  return 0;
}
 
int fib(int n){
  if(n==0 || n==1) return f[n]=1;
  if(f[n]!=NULL) return f[n];
  return f[n]=fib(n-2)+fib(n-1);
}