fibo.cpp

#include <iostream>
using namespace std;

int main() {
    int n;
    cout << "Enter Fibonacci index: ";
    cin >> n;
    if(n <= 1){
        cout << n << endl;
    }
    int t1 = 0, t2 = 1, t = 0;
    for (int i = 2; i < n; ++i) {
        t = t1 + t2;
        t1 = t2;
        t2 = t;
    }
    cout << t << endl;
    return 0;
}