#include <bits/stdc++.h> 
using namespace std;

#define sz(x) (int)x.size() 
#define pb push_back 
#define mp make_pair 
#define fi(a, b) for(int i=a; i<=b; i++) 
#define fj(a, b) for(int j=a; j<=b; j++) 
#define fo(a, b) for(int o=a; o<=b; o++) 
#define fdi(a, b) for(int i=a; i>=b; i--) 
#define fdj(a, b) for(int j=a; j>=b; j--) 
#define fdo(a, b) for(int o=a; o>=b; o--) 

#ifdef LOCAL
#define err(...) fprintf(stderr, __VA_ARGS__)
#else
#define err(...) while(false) {}
#endif

typedef long long ll; 
typedef pair<int, int> pii; 
typedef pair<ll, ll> pll; 
typedef vector<int> vi; 
typedef vector<ll> vll;
typedef vector<pii> vpii; 
typedef vector<pll> vpll; 
typedef long double ld;
typedef unsigned long long ull;

/////////////////////////////////

int const MAX = 2e5 + 41;

ll const INF = 1e18;

ll x[MAX];
ll s[MAX];
ll ans;

int n;

void solve() {
	fi(1, n) {
		ans = max(ans, s[i]);
	}

	ll b = -INF;
	ll sum = 0;

	fi(1, n) {
		ll prefr = sum + s[i];
		ll pans = prefr - x[i] + b;
		ans = max(ans, pans);
		b = max(b, x[i] - sum);
		sum += s[i];	
	}

	printf("%lld\n", ans);

}

int main() {
#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif

  scanf("%d", &n);
  fi(1, n) {
  	scanf("%lld %lld", &x[i], &s[i]);
  }
	solve();		

	
#ifdef LOCAL
	err("ELAPSED TIME: %.3Lf\n", (ld) clock() / CLOCKS_PER_SEC);
#endif	
	
	return 0;
}
### Prompt

Create a solution in CPP for 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 <bits/stdc++.h> 
using namespace std;

#define sz(x) (int)x.size() 
#define pb push_back 
#define mp make_pair 
#define fi(a, b) for(int i=a; i<=b; i++) 
#define fj(a, b) for(int j=a; j<=b; j++) 
#define fo(a, b) for(int o=a; o<=b; o++) 
#define fdi(a, b) for(int i=a; i>=b; i--) 
#define fdj(a, b) for(int j=a; j>=b; j--) 
#define fdo(a, b) for(int o=a; o>=b; o--) 

#ifdef LOCAL
#define err(...) fprintf(stderr, __VA_ARGS__)
#else
#define err(...) while(false) {}
#endif

typedef long long ll; 
typedef pair<int, int> pii; 
typedef pair<ll, ll> pll; 
typedef vector<int> vi; 
typedef vector<ll> vll;
typedef vector<pii> vpii; 
typedef vector<pll> vpll; 
typedef long double ld;
typedef unsigned long long ull;

/////////////////////////////////

int const MAX = 2e5 + 41;

ll const INF = 1e18;

ll x[MAX];
ll s[MAX];
ll ans;

int n;

void solve() {
	fi(1, n) {
		ans = max(ans, s[i]);
	}

	ll b = -INF;
	ll sum = 0;

	fi(1, n) {
		ll prefr = sum + s[i];
		ll pans = prefr - x[i] + b;
		ans = max(ans, pans);
		b = max(b, x[i] - sum);
		sum += s[i];	
	}

	printf("%lld\n", ans);

}

int main() {
#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif

  scanf("%d", &n);
  fi(1, n) {
  	scanf("%lld %lld", &x[i], &s[i]);
  }
	solve();		

	
#ifdef LOCAL
	err("ELAPSED TIME: %.3Lf\n", (ld) clock() / CLOCKS_PER_SEC);
#endif	
	
	return 0;
}
```