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 <bits/stdc++.h>
using namespace std;

#define int long long

#define rep(i,s,n) for(int i = s;i<n;i++)
#define repe(i,s,n) for(int i = s;i<=n;i++)
#define rrep(i,s,n) for(int i = (n)-1;i>=(s);i--)
#define all(v) (v).begin(),(v).end()
#define pb push_back
#define fi first
#define se second
typedef long long ll;
typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
typedef pair<pint,int> P1;
typedef pair<int,pint> P2;
static const ll maxLL = (ll)1 << 62;
const ll MOD=1000000007;
const ll INF=1e18;
int dy[]={-1,0,1,0};
int dx[]={0,1,0,-1};

int n;
int dp[55];

signed main(){
    cin.tie(0);
	ios::sync_with_stdio(false);
    cin>>n;
    dp[0]=1;
    dp[1]=1;
    rep(i,2,n+1){
        dp[i]=dp[i-1]+dp[i-2];
    }
    cout<<dp[n]<<endl;
    
    
    
    
    
    
    return 0;
}

C++: #include <iostream>

using namespace std;

int main()
{
    int n;
    int F[50];

    cin >> n;
    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 argc, char const *argv[])
{
  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(void)
{
    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];
    }
    cout<<dp[n]<<endl;
    return 0;
}

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

#define rep(i, n) for (int i = 0; i < n; ++i)

int main()
{
    int n;
    cin >> n;
    vector<int> fib(n + 1, 1);
    rep(i, n - 1)
    {
        fib[i + 2] = fib[i] + fib[i + 1];
    }

    cout << fib[n] << endl;

    return 0;
}

C++: #include <iostream>
using namespace std;
#define MAX 44

int F[MAX];

void Fibonacci(){
  F[0] = 1; F[1] = 1;
  for( int i = 2 ; i < MAX ; i++ ) F[i] = F[i-2] + F[i-1];
}

int main(void){
  Fibonacci();
  int i;

  cin >> i;
  cout << F[i] << endl;

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int n;
int f[50];
int fib(int k){
	 if (f[k]!=-1)
	    return f[k];
     if (k==0 || k==1) return 1;
	 f[k]=fib(k-1)+fib(k-2);
	 return f[k];	 
}
int main(){
	cin>>n;
	memset(f,-1,sizeof(f));
	cout<<fib(n)<<endl;
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
int num[50];
int fun(int k)
{
    if(num[k]) return num[k];
    if(k==0||k==1) return num[k]=1;
    return num[k]=fun(k-1)+fun(k-2);
}
int main()
{
    int n;
    scanf("%d",&n);
    printf("%d\n",fun(n));
    return 0;
}

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

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP0(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REP1(i,n) for(int i=1, i##_len=(n); i<=i##_len; ++i)
#define RREP0(i,n) for(int i=n-1; i>=0; --i)
#define RREP1(i,n) for(int i=n; i>=1; --i)

#define SORT(c) sort((c).begin(),(c).end())
#define whole(f,x,...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x)
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define CLR(a) memset((a), 0 ,sizeof(a))

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef long long LL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;

const int INTINF = 2147483647;
const LL LLINF = 9223372036854775807;
const double EPS = 1e-10;
const double PI  = acos(-1.0);

int gcd(int a,int b){return b?gcd(b,a%b):a;}
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
VI F;

int main(int argc, char const *argv[]) {
  cin.tie(0); ios::sync_with_stdio(false);
  int n; std::cin >> n;
  F.reserve(100);
  F.PB(1); F.PB(1);
  for (int i = 2; i <= n; i++) {
    F.PB(F[i-1]+F[i-2]);
  }
  std::cout << F[n] << '\n';
  return 0;
}

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

using namespace std;

#define MAX 45
#define NIL -1
int Memo[MAX];

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

int main() {
    int n;
    scanf("%d", &n);
    fill_n(Memo, MAX, NIL);
    printf("%d\n", fibonacci(n));
}

C++: #include <iostream>
int main(){
    int n;
    std::cin >> n;
    int dp[n + 1];
    if(n == 0 || n == 1){
        std::cout << 1 << std::endl;
        return 0;
    }
    dp[0] = 1;
    dp[1] = 1;
    for(int i = 2; i < n + 1; i++){
        dp[i] = dp[i - 1] + dp[i - 2];
    }
    std::cout << dp[n] << std::endl;
}

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

int Fibonatch(int result[], int num)
{
    int ret = result[num];

    if (ret != 0) {
        if (num > 1) {
            ret = Fibonatch(result, num - 1) + Fibonatch(result, num - 2);
        }
        else {
            ret = 1;
        }
        result[num] = ret;
    }

    return ret;
}

int main(void)
{
    int num;
    int ret[45] = {0};

    scanf("%d", &num);
    result = Fibonatch(ret, num);
}

C++: #include<iostream>
using namespace std;
using ll = long long;
int fib[100];
int main(){
  ll n;
  cin >> n;
  fib[0] = 1;
  fib[1] = 1;
  for (ll i = 0; i < n; i++) {
    fib[i+2] = fib[i+1] + fib[i];
  }

  cout << fib[n] << endl;
  
  return 0;
}