Capture

In a long narrow forest stretching east-west, there are N beasts. Below, we will call the point that is p meters from the west end Point p. The i-th beast from the west (1 ≤ i ≤ N) is at Point x_i, and can be sold for s_i yen (the currency of Japan) if captured.

You will choose two integers L and R (L ≤ R), and throw a net to cover the range from Point L to Point R including both ends, [L, R]. Then, all the beasts in the range will be captured. However, the net costs R - L yen and your profit will be (the sum of s_i over all captured beasts i) - (R - L) yen.

What is the maximum profit that can be earned by throwing a net only once?

Constraints

• 1 ≤ N ≤ 2 × 10^5
• 1 ≤ x_1 < x_2 < ... < x_N ≤ 10^{15}
• 1 ≤ s_i ≤ 10^9
• All input values are integers.

Input

Input is given from Standard Input in the following format:

N x_1 s_1 x_2 s_2 : x_N s_N

Output

When the maximum profit is X yen, print the value of X.

Examples

Input

5 10 20 40 50 60 30 70 40 90 10

Output

90

Input

5 10 2 40 5 60 3 70 4 90 1

Output

5

Input

4 1 100 3 200 999999999999999 150 1000000000000000 150

Output

299

inputFormat

input values are integers.

Input

Input is given from Standard Input in the following format:

N x_1 s_1 x_2 s_2 : x_N s_N

outputFormat

Output

When the maximum profit is X yen, print the value of X.

Examples

Input

5 10 20 40 50 60 30 70 40 90 10

Output

90

Input

5 10 2 40 5 60 3 70 4 90 1

Output

5

Input

4 1 100 3 200 999999999999999 150 1000000000000000 150

Output

299

样例

4
1 100
3 200
999999999999999 150
1000000000000000 150

299