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++: /*
 * Problem Description: Dynamic Programming - Fibonacci Number
 * Category:
 * Author: Khan
 * Date: 18th October, 2017
 */

#include <iostream>

using namespace std;

int n;
int Fibonacci[45];

int main(int argc, char const *argv[])
{
    //freopen("sample.txt", "r", stdin);
    cin >> n;
    Fibonacci[0] = 1;
    Fibonacci[1] = 1;
    for (int i = 2; i <= n; ++i)
    {
        Fibonacci[i] = Fibonacci[i - 1] + Fibonacci[i - 2];
    }
    cout << Fibonacci[n] << endl;
    return 0;
}

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

using namespace std;

int fib(int);

vector<int> num;

int main(){
    int n;
    cin >> n;
    
    num.resize(n, 0);
    
    cout << fib(n) << endl;
}

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

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

int f[45];

int fib(int n)
{
    if (n == 1 || n == 0)
        return 1;
    if (f[n] != -1)
        return f[n];

    return (f[n] = fib(n - 1) + fib(n - 2));
}

int main()
{
    int n;
    cin >> n;

    for (int i = 0; i < 46; i++)
        f[i] = -1;

    cout << fib(n) << endl;
}

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

typedef long long ll;

int main()
{
    ll i,j;
    ll n;
    cin >> n;
    vector<ll> Fib(n+1,1);
    for(i = 2;i <= n;++i){
        Fib.at(i) = Fib.at(i-1) + Fib.at(i-2);
    }
    cout << Fib.at(n) << endl;

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define FOR(i,x,n) for(int i=x; i<(n); i++)
#define ALL(n) begin(n),end(n)
#define MOD (1000000007)
#define INF (1e9)
#define INFL (1e18)
 
typedef long long ll;
typedef unsigned int ui;
typedef unsigned long long ull;
template<class T>using arr=vector<vector<T>>;
template<class T>void pr(T x){cout << x << endl;}
template<class T>void prvec(vector<T>& a){rep(i, a.size()-1){cout << a[i] << " ";} cout << a[a.size()-1] << endl;}
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
 
vector<ll> fibs(100, -1);
ll fib(int n){
    if(fibs[n]!=-1) return fibs[n];
    if(n==0 || n==1) return 1;

    return fibs[n] = fib(n-2) + fib(n-1);
}

int main()
{
    int n; cin >> n;
    pr(fib(n));
    return 0;}

C++: #include<bits/stdc++.h>
using namespace std;
int main(){
    int f1=0,f2=1,n,xx;
    cin>>n;
    for (int i=1;i<=n;i++)
    {
       xx=f2;
        int next = f1 + f2;
        f1 = f2;
        f2 = next;
}
printf("%d\n",f2);
}

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

#define fs first
#define sc second
#define pb emplace_back
#define mp make_pair
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)

using pii = pair<int, int>;
using vi = vector<int>;
using lint = long long;

const int inf = 1001001001;
const lint linf = 1001001001001001001ll;
const int mod = 1e9 + 7;
const int dx[]{0, 1, 0, -1, -1, -1, 1, 1}, dy[]{1, 0, -1, 0, -1, 1, -1, 1};

template<typename T> inline bool chmin(T &a, T b) { if (a > b) { a = b; } return a > b; }
template<typename T> inline bool chmax(T &a, T b) { if (a < b) { a = b; } return a < b; }
template<typename T> inline void print(const T &x, string s = "\n") { cout << x << s; }
template<typename T> inline void print(const vector<T> &v, string s = " ")
{ if (!v.size()) puts(""); rep(i, v.size()) cout << v[i] << (i + 1 == v.size() ? "\n" : s); }
inline bool inside(int y, int x, int H, int W) { return 0 <= y && y < H && 0 <= x && x < W; }
inline lint in() { lint x; std::cin>>x; return x; }

vector<lint> Fib{0, 1, 1};
lint fib(int k) {
  if (k < 0) return 0;
  if (k == 0) return 0;
  if (k < 3) return 1;
  if (Fib.size() <= k + 1) {
    Fib.push_back(fib(k - 1) + fib(k - 2) /* % mod */);
  }

  return Fib[k];
}

signed main() {
  cout << fib(in() + 1) << endl;
}

C++: #include <iostream>
#include <vector>
#define eol '\n'
using namespace std;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  
  int n;
  cin >> n;

  vector<int> list(n,0);
  list[0] = list[1] = 1;
  

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

  cout << list[n] << eol;
  
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rp(i,j) for(long long i=0;i<j;i++)
#define rep(i,j,k) for(long long i=j;i<k;i++)
#define mod 1000000007
typedef long long ll;
int main(){
    int n;cin>>n;
    int dp[50];
    rp(i,50){
        if(i==0||i==1)dp[i]=1;
        else dp[i]=dp[i-1]+dp[i-2];
    }
    cout<<dp[n]<<endl;
}

C++: #include "iostream"

using namespace std;

int F[46];

int fib( int n ) {

	if (F[n] != 0) return F[n];

	if (n == 0 || n == 1) F[n] = 1;

	else F[n] = fib(n - 1) + fib(n - 2);

	return F[n];
}

int main() {


	int n;

	cin >> n;

	cout << fib(n) << endl;

	return 0;
}

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

int dp[50];

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

int main(void){
  int n; cin >> n;
  rep(i,50) dp[i] = -1;
  cout << fibonacci(n) << endl;
  return 0;
}

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

int main(){
    int n;
    cin >> n;
    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[n]<<endl;

    return 0;
}

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

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

C++: #include <iostream>
int F[100];
int main() 
{
int n;
F[0] = 1;
F[1] = 1;
for (int i=2; i<45; ++i) 
{ // ???????????????
F[i] = F[i-2]+F[i-1];
}
cin>>n;
cout<<F[n];
}