双倍经验 P2949 已过，用的是 multiset 维护。

#pragma GCC optimize(3, "Ofast", "inline")
#include <iostream>
#include <cassert>
#include <queue>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <ctime>
#include <map>
#include <set>
using namespace std;
// #define int long long
#define debug puts("qwq")
#define open(x) freopen(#x".in", "r", stdin);freopen(#x".out", "w", stdout);
#define close fclose(stdin);fclose(stdout);
namespace FastIO {
	template <typename T = int>
	inline T read() {
		T s = 0, w = 1;
		char c = getchar();
		while (!isdigit(c)) {
			if (c == '-') w = -1;
			c = getchar();
		}
		while (isdigit(c)) s = (s << 1) + (s << 3) + (c ^ 48), c = getchar();
		return s * w;
	}
	template <typename T>
	inline void read(T &s) {
		s = 0;
		int w = 1;
		char c = getchar();
		while (!isdigit(c)) {
			if (c == '-') w = -1;
			c = getchar();
		}
		while (isdigit(c)) s = (s << 1) + (s << 3) + (c ^ 48), c = getchar();
		s = s * w;
	}
	template <typename T, typename... Arp> inline void read(T &x, Arp &...arp) {
		read(x), read(arp...);
	}
	template <typename T>
	inline void write(T x, char ch) {
		if (x < 0) x = -x, putchar('-');
		static char stk[25];
		int top = 0;
		do {
			stk[top++] = x % 10 + '0', x /= 10;
		} while (x);
		while (top) putchar(stk[--top]);
		putchar(ch);
		return;
	}
	template <typename T>
	inline void smax(T &x, T y) {
		if (x < y) x = y;
	}
	template <typename T>
	inline void smin(T &x, T y) {
		if (x > y) x = y;
	}
	void quit() {
		exit(0);
	}
} using namespace FastIO;
vector<int> g[101010];
int lsh[101010];
struct node { int x, y; } a[101010];
signed main() { int n;
	while (~scanf("%d", &n)) {
	int ans=0;
	for (int i=1;i<=n;++i) a[i].y=read(),lsh[i]=a[i].x=read();
	sort(lsh+1,lsh+1+n);
	int len=unique(lsh+1,lsh+1+n)-lsh-1;
	for (int i=1;i<=len;++i) g[i].clear();
	for (int i=1;i<=n;++i) {
		g[lower_bound(lsh+1,lsh+1+len,a[i].x)-lsh].push_back(a[i].y);
	}
	multiset<int, greater<int> > st;
	for (int i=len;i;--i) {
		for (auto j:g[i]) st.insert(j);
		int x=lsh[i]-lsh[i-1];
		while (x-- && st.size()) {
			ans += *st.begin(); st.erase(st.begin());
		}
	} write(ans, '\n'); }
	return 0;
}