Marbles
Rohit
dreams he is in a shop with an infinite amount of marbles. He is allowed to
select n marbles. There are marbles of k different colors. From each color,
there are also infinitely many marbles. Rohit wants to have at least one marble
of each color, but still there are many possibilities for his selection. In his
effort to make a decision, he wakes up. Now he asks you how many possibilities
for his selection he would have had. Assume that marbles of equal color cannot
be distinguished, and the order of the marbles is irrelevant.
Input
The
first line of input contains a number T <= 100 that indicates the number of
test cases to follow. Each test case consists of one line containing n and k,
where n is the number of marbles Rohit selects and k is the number of different
colors of the marbles. You can assume that 1<=k<=n<=1000000.
Output
For
each test case, print the number of possibilities that Rohit would have had.
You can assume that this number fits into a signed 64-bit integer.
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Sample Input1:
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Sample Input2:
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2
10 10
30 7
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1
3 2
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Sample Output1:
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Sample Output2:
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1
475020
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2
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Для отправки решений необходимо