// C++ program to check if x is a perfect square 

#include <iostream> 
#include <math.h> 
using namespace std; 

// A utility function that returns true if x is perfect square 
bool isPerfectSquare(int x) { 
    int s = sqrt(x); 
    return (s*s == x); 
} 

// Returns true if n is a Fibinacci Number, else false 
bool isFibonacci(int n) { 
    // n is Fibinacci if one of 5*n*n + 4 or 5*n*n - 4 or both 
    // is a perferct square 
    return isPerfectSquare(5*n*n + 4) || isPerfectSquare(5*n*n - 4); 
} 

// A utility function to test above functions 
int main() { 
    for (int i = 1; i <= 10; i++) 
        isFibonacci(i)? cout << i << " is a Fibonacci Number \n": 
                        cout << i << " is a not Fibonacci Number \n" ; 
    return 0; 
}