Number of Passengers in Train
A train leaves the first station with N
passengers and visits K stations before it arrives at the last station.
In each station some passengers got off
the train and some passengers got on the train. Everybody in the train got off
at the last station.
Make a program that calculates how many
passengers got off the train at the last station.
Input:
The first line of the input has two
integers K and N.
Each of the following K lines contains
two integers, the first one denotes the number of passengers who got off the
train at that station, and the second one denotes the number of passengers got
on the train at that station.
Output:
The output should have a single integer
that is number of passengers who got off the train at the last station.
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Sample Input1:
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Sample Input2:
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2 5
3 6
2 4
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5 20
6 15
5 30
20 12
15 8
6 7
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Sample Output1:
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Sample Output2:
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10
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40
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Для отправки решений необходимо