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E. Martian Luck

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputYou know that the Martians use a number system with base *k*. Digit *b* (0 ≤ *b* < *k*) is considered lucky, as the first contact between the Martians and the Earthlings occurred in year *b* (by Martian chronology).

A digital root *d*(*x*) of number *x* is a number that consists of a single digit, resulting after cascading summing of all digits of number *x*. Word "cascading" means that if the first summing gives us a number that consists of several digits, then we sum up all digits again, and again, until we get a one digit number.

For example, *d*(3504_{7}) = *d*((3 + 5 + 0 + 4)_{7}) = *d*(15_{7}) = *d*((1 + 5)_{7}) = *d*(6_{7}) = 6_{7}. In this sample the calculations are performed in the 7-base notation.

If a number's digital root equals *b*, the Martians also call this number lucky.

You have string *s*, which consists of *n* digits in the *k*-base notation system. Your task is to find, how many distinct substrings of the given string are lucky numbers. Leading zeroes are permitted in the numbers.

Note that substring *s*[*i*... *j*] of the string *s* = *a*_{1}*a*_{2}... *a*_{n} (1 ≤ *i* ≤ *j* ≤ *n*) is the string *a*_{i}*a*_{i + 1}... *a*_{j}. Two substrings *s*[*i*_{1}... *j*_{1}] and *s*[*i*_{2}... *j*_{2}] of the string *s* are different if either *i*_{1} ≠ *i*_{2} or *j*_{1} ≠ *j*_{2}.

Input

The first line contains three integers *k*, *b* and *n* (2 ≤ *k* ≤ 10^{9}, 0 ≤ *b* < *k*, 1 ≤ *n* ≤ 10^{5}).

The second line contains string *s* as a sequence of *n* integers, representing digits in the *k*-base notation: the *i*-th integer equals *a*_{i} (0 ≤ *a*_{i} < *k*) — the *i*-th digit of string *s*. The numbers in the lines are space-separated.

Output

Print a single integer — the number of substrings that are lucky numbers.

Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

Examples

Input

10 5 6

3 2 0 5 6 1

Output

5

Input

7 6 4

3 5 0 4

Output

1

Input

257 0 3

0 0 256

Output

3

Note

In the first sample the following substrings have the sought digital root: *s*[1... 2] = "3 2", *s*[1... 3] = "3 2 0", *s*[3... 4] = "0 5", *s*[4... 4] = "5" and *s*[2... 6] = "2 0 5 6 1".

Codeforces (c) Copyright 2010-2018 Mike Mirzayanov

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