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>
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define nyan "(=^･ω･^=)"
using namespace std;

const int mod = 1e9 + 7;
const long long INF = 1LL<<60;
//using ll = long long;
//using P = pair<int,int>;

long long dp[50];

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

int main(){
    int n;
    cin >> n;
    
    dp[0] = 1, dp[1] = 1;
    
    cout << fibonacci(n) << endl;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <algorithm>
//#include <cmath>
//#include <iomanip>
//#include <map>
//#include <unordered_map>
//#include <cstring>
#include <queue>

using namespace std;
using ll = long long;
// using pint = pair<int, int>;
// ll INF = 1LL << 60;

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

C++: # include <iostream>
using namespace std;
int main(void)
{
	int a[50] = {1,1},n;
	for(int i = 2;i < 50;i++) a[i] = a[i-1]+a[i-2];
	cin>>n; cout<<a[n]<<endl;
	return 0;
}

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

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;

#define MOD 1000000007
#define REP(i, N) for (int i = 0; i < N; ++i)
#define REP1(i, N) for (int i = 1; i <= N; ++i)
#define RREP(i, N) for (int i = N - 1; i >= 0; --i)
#define ALL(a) a.begin(), a.end()

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>
#include <string>
#include <sstream>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <cstring>
#include <cstdio>
#include <cmath>

using namespace std;

int f(const int);

int main()
{
    int N;
    cin>>N;
    cout<<f(d)<<endl;
}
int f(const int d)
{
    if(d<2)return 1;
    return f(d-1)+f(d-2);
}

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

using namespace std;

vector<int>dp;

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

int main() {
    int n;
    cin >> n;
    dp.resize(n+1);
    for (int i = 0; i <= n; ++i) dp[i] = -1;
    dp[0] = 1;
    dp[1] = 1;
    cout << fib_dp(n) << endl;
    return 0;
}

C++: #include <iostream>

using namespace std;

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

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

vector<int> F(45, -1);
int fib(int n) {
  if (F[n] != -1)
    return F[n];
  else if (n == 1 || n == 0) {
    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;
}

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

typedef long int lint;
typedef long long int llint;
typedef pair<int, int> pii;
typedef pair<int, string> pis;
typedef pair<long, long> pll;

#define EACH(i, c) for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define ALL(c) (c).begin(), (c).end()
#define FOR(i, s, e) for (int i = (s); i < (int)(e); ++i)
#define REP(i, n) FOR(i, 0, n)
#define endl "\n"

const int INF = 100000000;
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

template<typename T>
void print(const std::vector<T>& v, char sep=' ') {
  for (int i = 0; i < (int)v.size(); i++) {
    if (i != 0) cout << sep;
    cout << v[i];
  }
  cout << endl;
}

int fib[45];

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

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

C++: #include<iostream>
#include<cmath>
#include<algorithm>
#include<vector>
#include<queue>

using namespace std;

int main(){

  int n;
  cin >> n;

  int fib[50];
  fib[0]=1,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>
using namespace std;

int Fibonacci(int n) {
    int F[45];
    F[0] = 1;
    F[1] = 1;
    for(int i = 2; i <= n; i++) {
        F[i] = F[i-1] + F[i-2];
    }
    return F[n];
}

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

C++: #include <iostream>

using namespace std;

int fib(int n) {
    int a = 1;
    int b = 1;

    int i = 0;
    while (i < n) {
        a = b;
        b = a + b;
        ++i;
    }
    return a;
}

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

    cout << fib(n) << endl;

    return 0;
}

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

int main()
{
int n;cin>>n;//scanf("%d",&n);
int fib[n+1];//vector<int> fib(n+1,1);
for(int i=0;i<n+2;i++)fib[i]=1;
if(n>1){for(int i=2;i<n+2;i++){fib[i]=fib[i-2]+fib[i-1];}}
cout<<fib[n]<<endl;//printf("%d\n",fib[n]);
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<bitset>
#include<cctype>
#include<climits>
#include<cmath>
#include<cstdio>
#include<deque>
#include<list>
#include<map>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<queue>
#include<vector>
using namespace std;

int F[45] = {};

int fib(int n) {
	if (n == 0 || n == 1)
		return F[n] = 1;
	else
		return F[n] ? F[n] : F[n] = fib(n - 1) + fib(n - 2);
}

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

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

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

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