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>
using namespace std;
long long dp[45];
int main(){
    int n;cin>>n;
    dp[0]=1;
    dp[1]=1;
    for(int i = 2; n >= i; i++){
        dp[i] = dp[i-1]+dp[i-2];
    }
    cout << dp[n] << endl;
}

C++: #include <iostream>

using namespace std;


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

}

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

C++: w#include <stdio.h>
int fib(int);
int fibo[45];
int main(){
  int n,i;
  for(i=0;i<45;i++)fibo[i]=-1;
  scanf("%d",&n);
  printf("%d\n",fib(n));
  return 0;
}
int fib(int n){
  if(n==0 || n==1)return fibo[n]=1;
  if(fibo[n]!=-1)return fibo[n];
  return fibo[n]=fib(n-1)+fib(n-2);
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef  long long ll;
using vll=vector<ll>;
using vi=vector<int>;
using vb=vector<bool>;
using pii=pair<int,int>;

template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;}
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;}

//pow(llpow,modpow)
template<class T> ll llpow(ll x,T n){ll ans=1;if(x==0)ans=0;while(n){if(n&1)ans*=x;x*=x;n>>=1;}return ans;}
long long modpow(long long a, long long n, long long mod) {long long res = 1;while (n > 0) {if (n & 1) res = res * a % mod;a = a * a % mod;n >>= 1;}return res;}
//最大公約数
template<class T> inline T gcd(T x,T y){if(y==0)return x; else {return gcd(y,x%y);}}
//最小公倍数
template<class T> inline T lcm(T x,T y){return x/gcd(x,y)*y;}
//逆元
long long modinv(long long a, long long m) {long long b = m, u = 1, v = 0;while (b) {long long t = a / b;a -= t * b; swap(a, b);u -= t * v; swap(u, v);}u %= m;if (u < 0) u += m;return u;}

#define rep(i, begin_i, end_i) for (ll i = (ll)begin_i; i < (ll)end_i; i++)

long long INF = 1LL<<60;


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

C++: #include<bits/stdc++.h>
using namespace std;
int F[45];
int f(int n){
	if(n==1||n==0)	return F[n]=1;
	if(F[n])	return F[n];
	else return F[n]=f(n-1)+f(n-2);
}
int main(){
	int n;
	cin>>n;
	cout<<f(n)<<endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define int lint
typedef long long lint;
typedef pair<int,int> P;
const int    INF=(int)1e9;
const int    MOD=(int)1e9+7;
const double EPS=(double)1e-10;
struct Accelerate_Cin{
    Accelerate_Cin(){
        cin.tie(0); ios::sync_with_stdio(0);cout<<fixed<<setprecision(20);
    };
};



signed main(){
  int n;cin>>n;
  int dp[100];

  dp[0]=dp[1]=1;
  for(int t=2;t<=n;t++){
    dp[t]=dp[t-1]+dp[t-2];
  }

  cout<<dp[n]<<"\n";
  return 0;
}

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

int main(){
  int a[50],s;
  cin>>s;
  a[0]=1;
  a[1]=1;
  for(int i=2;i<=s;i++){
    a[i]=a[i-1]+a[i-2];
  }
  cout<<a[s]<<endl;
  return 0;
}

C++: #include <bits/stdc++.h>
typedef long long ll;
using namespace std;
ll MOD = 1000000007;

#define vec                vector<int>
#define vecll              vector<ll>
#define vecd               vector<double>
#define vecst              vector<string>
#define vecb               vector<bool>
#define vec2(var, n, m)    vector<vector<int>> var(n, vector<int>(m, 0))
#define vecll2(var, n, m)  vector<vector<ll>> var(n, vector<ll>(m, 0))

#define rep(i,n)         for(ll i=(ll)0; i<(ll)n; i++)
#define REP(i,m,n)       for(ll i=(ll)m; i<(ll)n; i++)
#define arr(var, n)      vec var(n); rep(i,n){cin >> var[i];}
#define arrll(var, n)    vecll var(n); rep(i,n){cin >> var[i];}
#define arrst(var, n)    vecst var(n); rep(i,n){cin >> var[i];}
#define all(var)         (var).begin(), (var).end()
#define sortall(var)     sort(all(var))
#define uniqueall(v)     v.erase(unique(v.begin(), v.end()), v.end());
#define f_sum(var)       accumulate(all(var), 0)
#define f_sumll(var)     accumulate(all(var), 0LL)
#define chmin(v1, v2)    v1 = min(v1, v2)
#define chmax(v1, v2)    v1 = max(v1, v2)
#define pb(var)          push_back(var)
#define prt(var)         cout << (var) << "\n"
#define prtd(n, var)     cout << fixed << setprecision(n) << (var) << "\n"
#define prtfill(n, var)  cout << setw(n) << setfill('0') << (var);
#define prt2(v1, v2)     cout << (v1) << " " << (v2) << "\n"
#define prt3(v1, v2, v3) cout << (v1) << " " << (v2) << " " << (v3) << "\n"
#define prtall(v)        rep(i,v.size()){cout<<v[i]<<(i!=v.size()-1?" ":"\n");}
void prtok(bool ok){prt(ok ? "Yes" : "No");}
//----------------------------------------------------------------

int main(void) {
  int n;
  cin >> n;
  int dp[50];
  dp[0]=1;
  dp[1]=1;
  rep(i,47){
    dp[i+2]=dp[i+1]+dp[i];
  }
  prt(dp[n]);
}

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

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

    int fib[n+1];
    rep(i, n+1) fib[i] = 0;

    fib[0] = fib[1] = 1;
    rep(i, n+1)
    {
        if(i >= 2) fib[i] += fib[i-1] + fib[i-2];
    }
    
    cout << fib[n] << endl;
    return 0;
}

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

int main(){
    int F[44];
    F[0]=1;
    F[1]=1;
    int n;
    cin>>n;
    for(int i=2;i<=n;++i){
        F[i]=F[i-1]+F[i-2];
    }
    cout<<F[n]<<"\n";
}