Error identifier 'time' is undefined

/ This program predicts the player's future using
// random numbers and an if/else if statement.
#include <iostream>
#include <cstdlib>			// Needed for random numbers
#include < stdio.h>
#include <string>
using namespace std;

int main()
{
	string career1, career2, career3;

	int randomNum;			// Will hold the randomly generated integer
	
	// "Seed" the random gererator
	
	unsigned seed = time(0);
	srand(seed);

	// Explain the game and get the player's career choices
	cout << "I am a fortune teller. Look into my crystal screen \n"
		 << "and enter 3 careers you would like to have. Example: \n\n"
		 << "      chef \n      astronaut \n      CIA agent \n\n"
		 << "Then I will predict what you will be. \n\n";

	cout << "Career choice 1: ";
	getline(cin, career1);
	cout << "Career choice 2: ";
	getline(cin, career2);
	cout << "Career choice 3: ";
	getline(cin, career3);

	// Randomly generate an integer between 1 and 4.
	randomNum = 1 + rand() % 4;

	// Use branching logic to output the prediction
	if (randomNum == 1)
		cout << "\nYou will be a " << career1 << ". \n";
	else if (randomNum == 2)
		cout << "\nYou will be a " << career2 << ". \n";
	else if (randomNum == 3)
		cout << "\nYou will be a " << career3 << ". \n";
	else
		cout << "\nSorry. You will not be any of these. \n";
	
	system ("pause");
	return 0;
	
}