Submission

Score: 100

User: pann

Problemset: Fibonacci Croissant

Language: cpp

Time: 0.002 second

Submitted On: 2026-10-05 01:06:23

#include <iostream>
using namespace std;


int main(){
    int n;
    cin >> n;
    long long n1 = 0, n2 = 1, sum = 1;
    for (int i = 0; i < n-1; i++){
        long long n3 = n1 + n2;
        sum += n3;
        n1 = n2;
        n2 = n3;
    }
    cout << sum;
    return 0;
}