A student has written a pseudocode algorithm to calculate the product of five numbers entered by the user.
1 SET product TO 0
2 SET counter TO 1
3 WHILE counter <= 5 DO
4 SEND 'Enter a number: ' TO DISPLAY
5 RECEIVE num FROM (INTEGER) KEYBOARD
6 SET product TO product * num
7 SET counter TO counter + 1
8 END WHILE
9 SEND 'The result is ' & product TO DISPLAY
Give the number of the line that contains the logic error.