In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question? 72 x 9 - 14 + 2 = ?
Students are sitting in a row in which the position of X is 17th from the left and that of Y is 14th from the right. If they interchange their positions, X's position becomes 7th from the left. How many students are there in the row?