/**
 * Given a list of economists, filter out the ones whose introduction does not contain the word "economics".
 *
 * @param economist List of economist names along with their introduction.
 * @return List of economist names whose introduction contains the word "economics".
 */
fun intersectionOfIntroductionAndIsNotOperator(economist: List<Pair<String, String>>): List<String> {

    return economist.filter { it.second.contains("economics") }.map { it.first }
}
/**
 * Given a list of economists, filter out the ones whose introduction does not contain the word "economics".
 *
 * @param economist List of economist names along with their introduction.
 * @return List of economist names whose introduction contains the word "economics".
 */
fun intersectionOfIntroductionAndIsNotOperator(economist: List<Pair<String, String>>): List<String> {
/**
 * Given a list of economists, filter out the ones whose introduction does not contain the word "economics".
 *
 * @param economist List of economist names along with their introduction.
 * @return List of economist names whose introduction contains the word "economics".
 */
fun intersectionOfIntroductionAndIsNotOperator(economist: List<Pair<String, String>>): List<String> {

    return economist.filter { it.second.contains("economics") }.map { it.first }
}