# Petya and Array

## 题目描述

Petya has an array $ a $ consisting of $ n $ integers. He has learned partial sums recently, and now he can calculate the sum of elements on any segment of the array really fast. The segment is a non-empty sequence of elements standing one next to another in the array.
Now he wonders what is the number of segments in his array with the sum less than $ t $ . Help Petya to calculate this number.
More formally, you are required to calculate the number of pairs $ l, r $ ( $ l \le r $ ) such that $ a_l + a_{l+1} + \dots + a_{r-1} + a_r < t $ .

## 输入输出格式

### 输入格式

The first line contains two integers $ n $ and $ t $ ( $ 1 \le n \le 200\,000, |t| \le 2\cdot10^{14} $ ).
The second line contains a sequence of integers $ a_1, a_2, \dots, a_n $ ( $ |a_{i}| \le 10^{9} $ ) — the description of Petya's array. Note that there might be negative, zero and positive elements.

### 输出格式

Print the number of segments in Petya's array with the sum of elements less than $ t $ .

## 输入输出样例

### 输入样例 #1

```
5 4
5 -1 3 4 -1
```

### 输出样例 #1

```
5
```

### 输入样例 #2

```
3 0
-1 2 -3
```

### 输出样例 #2

```
4
```

### 输入样例 #3

```
4 -1
-2 1 -2 3
```

### 输出样例 #3

```
3
```

## 说明

In the first example the following segments have sum less than $ 4 $ :
- $ [2, 2] $ , sum of elements is $ -1 $
- $ [2, 3] $ , sum of elements is $ 2 $
- $ [3, 3] $ , sum of elements is $ 3 $
- $ [4, 5] $ , sum of elements is $ 3 $
- $ [5, 5] $ , sum of elements is $ -1 $