#include <iostream>
using namespace std;

unsigned long long iterative_fib(int n){
   unsigned long long firstNumber = 0;
   unsigned long long secondNumber = 1;
   unsigned long long thirdNumber = 0;

   for (int i = 0; i < n-1; i++)
   {
       thirdNumber = firstNumber + secondNumber;
       firstNumber = secondNumber;
       secondNumber = thirdNumber;
   }
   return thirdNumber;
}

int main() {
   unsigned long long result = iterative_fib(79);
   cout << "The fibonacci number is: " << result;
   return 0;
}