#include <iostream>
#include <iomanip>
#include <vector>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <queue>
#include <deque>
#include <stack>
#include <algorithm>
#include <numeric>
#include <string>
#include <sstream>
#include <cmath>
#include <cstring>
#include <assert.h>
#include <utility>
#include <tuple>
#include <array>
#include <bitset>
#include <cstdlib>

using int64 = long long;

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int N;
    std::cin >> N;

    int64 sum_s = 0,
          ans = 0;

    std::priority_queue<int64> pque;
    for (int i = 0; i < N; i++) {
        int64 x, s;
        std::cin >> x >> s;

        pque.push(x - sum_s);

        sum_s += s;

        ans = std::max(ans, sum_s - x + pque.top());
    }
    std::cout << ans << std::endl;

    return 0;
}

### Prompt

In cpp, your task is to solve the following problem:

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

### Response

```cpp
#include <iostream>
#include <iomanip>
#include <vector>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <queue>
#include <deque>
#include <stack>
#include <algorithm>
#include <numeric>
#include <string>
#include <sstream>
#include <cmath>
#include <cstring>
#include <assert.h>
#include <utility>
#include <tuple>
#include <array>
#include <bitset>
#include <cstdlib>

using int64 = long long;

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int N;
    std::cin >> N;

    int64 sum_s = 0,
          ans = 0;

    std::priority_queue<int64> pque;
    for (int i = 0; i < N; i++) {
        int64 x, s;
        std::cin >> x >> s;

        pque.push(x - sum_s);

        sum_s += s;

        ans = std::max(ans, sum_s - x + pque.top());
    }
    std::cout << ans << std::endl;

    return 0;
}

```