This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.
#include <bits/stdc++.h>
//十年OI一场空，不开long long见祖宗~
using namespace std;
typedef long long LL;
int main() {
int n;
cin >> n;
LL a = 1, b = 1, c = 0;
for (int i = 3; i <= n; i++) {
c = a + b;
a = b;
b = c;
}
cout << c << ".00" << endl;
return 0;
