#include <iostream>
#include <cstring>
#include <cmath>
#include <math.h>
#include <vector>
#include <queue>
using namespace std;
long long dp[1005];
long long fib(int number) {
    if(number <= 2) {
        return 1;
    }
    if(dp[number] != -1) {
        return dp[number];
    }
    return dp[number] = fib(number - 1) + fib(number - 2);
}
int main()
{
    memset(dp, -1, sizeof dp);
    
    cout << fib(50) << endl;
    return 0;
}