A student has written an algorithm to calculate the sum of numbers up to a specified limit.

1 SET limit TO 0
2 SET total TO 0
3 SET counter TO 0
4
5 SEND "Enter a positive integer: " TO DISPLAY
6 RECEIVE limit FROM (INTEGER) KEYBOARD
7
8 IF (limit <= 0) THEN
9     SEND "Error: Must be positive" TO DISPLAY
10 ELSE
11     IF (limit = 1) THEN
12         SEND "The sum is 1" TO DISPLAY
13     ELSE
14         FOR counter FROM 1 TO limit DO
15             SET total TO total + counter
16         END FOR
17         SEND "The sum is " & total TO DISPLAY
18     ENDIF
19 ENDIF