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 <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;
}