Answer :
The program is an illustration of loops
What are loops?
Loops are program statements that are used to perform repetition
The main program
The program written in Python, where comments are used to explain each line is as follows:
#This initializes sum to 0
summ = 0
#This gets input for the first number
num = int(input())
#This is repeated while num is not -1
while num!= -1:
#This calculates the sum
summ+=num
#This gets input for the num
num = int(input())
#This prints the sum
print(summ)
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