Given the values of $n, k, m$, you have to check if there are $m$ distinct numbers in the range from 1 to $k$ have the sum $n$ or not ?
$n$ represents the required sum $k$ represents numbers range(1,2,3,... to k). $m$ is the number of elements in the range from 1 to $k$ that has the sum $n$.
Example: n = 12, k = 8, m = 3 ==> there are 3 numbers in the range from 1 to 8 that have the sum 12 which are 2,3,7.
The problem is taken from hackerrank and called bonetrousle.