C++ The Fibonacci sequence begins with 0 and then 1 follows. All subsequent values are the sum of the previous two, for example: 0, 1, 1, 2, 3,5, 8, 13. Complete the Fibonacci() function, which has an index, n, as parameter and returns the nth value in the sequence. Any negativeindex values should return-1.Ex: If the input is:7the output is:Fibonacci (7) is 13Note: Use a for loop and DO NOT use recursion.464730.3214874 qx3zqy7LABACTIVITY1 #include 2 using namespace std;4 int Fibonacci(int n) {8}896.24.1: LAB: Fibonacci sequence12131415CS/* Type your code here. */10 int main() {11int startNum;main.cpp4.cin >>startNum;cout << "Fibonacci (" << startNum << ") is " << Fibonacci (startNum) << endl;return 0;Diequr negaran0/10Load default template...

Function: int Fibonacci(int n) { if (n < 0) { return -1; // Return -1 for negative…

The Fibonacci sequence begins with 0 and then 1 follows. All subsequent values are the sum of the previous two, for example: 0, 1, 1, 2, 3, 5, 8, 13. Complete the Fibonacci() function, which has an index, n, as parameter and returns the nth value in the sequerice. Any negative index values should return -1.