#include <iostream>
using namespace std;
int mem[10] = {0};
int fib(int n) {
    if(n == 1 || n == 2) return 1;
    if(mem[n] != 0) return mem[n];
    mem[n] = fib(n-1) + fib(n-2);
    return mem[n];
}
int main() {
    cout << fib(6) << endl;
    return 0;
}