At the University of Squirreloo, first-year squirrels in the math faculty have to take MATH 137: calculus, everyone's favourite branch of math! In this course they learn about convergent sequences, where values in a sequence get arbitrarily close to a limit. However, said sequences are infinite, and infinity is a concept too difficult to tackle immediately for our young squirrels, so they'll first discuss sequences of finite length - namely, an array of length . We'll say an array
converges to a limit
with an accuracy of
if there exists a suffix
of
such that all elements in
differ from
by at most
. Given an array
of length
, the squirrels are given
assignment questions of the form
, and are tasked to determine whether or not
converges to
with an accuracy of
, and if so, to find the length of the longest suffix of
that fulfills the definition above.
Constraints
For this problem, you will be required to pass all the samples in order to receive any points. In addition, you must pass all previous subtasks to earn points for a specific subtask.
For all subtasks:
for all
Subtask 1 [18%]
Subtask 2 [82%]
No additional constraints.
Input Specification
On the first line will be two integers and
, the length of the array and the number of assignment questions respectively.
The second line will contain integers
, the array
.
The following lines will each contain two integers
and
, the limit and accuracy to test for on the
assignment question.
Output Specification
This problem is graded with an identical
checker. This includes whitespace characters. Ensure that every line of output is terminated with a \n
character and that there are no trailing spaces.
Output lines. The
line should contain the length of the longest suffix of
such that all elements in the suffix differ from
by at most
. If such a suffix does not exist, output
.
Sample Input 1
8 5
1 5 4 6 -2 3 4 0
0 4
2 2
1 5
-1 0
5 5
Sample Output 1
4
3
8
0
3
Sample Input 2
5 5
1 2 3 4 5
5 1
4 1
2 2
2 3
1 5
Sample Output 2
2
3
0
5
5
Comments
off-by-ones make my brain hurt