#D61. Meaningful Mean
Meaningful Mean
Meaningful Mean
You are given an integer sequence of length N, a = {a_1, a_2, …, a_N}, and an integer K.
a has N(N+1)/2 non-empty contiguous subsequences, {a_l, a_{l+1}, …, a_r} (1 ≤ l ≤ r ≤ N). Among them, how many have an arithmetic mean that is greater than or equal to K?
Constraints
- All input values are integers.
- 1 ≤ N ≤ 2 \times 10^5
- 1 ≤ K ≤ 10^9
- 1 ≤ a_i ≤ 10^9
Input
Input is given from Standard Input in the following format:
N K a_1 a_2 : a_N
Output
Print the number of the non-empty contiguous subsequences with an arithmetic mean that is greater than or equal to K.
Examples
Input
3 6 7 5 7
Output
5
Input
1 2 1
Output
0
Input
7 26 10 20 30 40 30 20 10
Output
13
inputFormat
input values are integers.
- 1 ≤ N ≤ 2 \times 10^5
- 1 ≤ K ≤ 10^9
- 1 ≤ a_i ≤ 10^9
Input
Input is given from Standard Input in the following format:
N K a_1 a_2 : a_N
outputFormat
Output
Print the number of the non-empty contiguous subsequences with an arithmetic mean that is greater than or equal to K.
Examples
Input
3 6 7 5 7
Output
5
Input
1 2 1
Output
0
Input
7 26 10 20 30 40 30 20 10
Output
13
样例
1 2
1
0