#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>#include <algorithm>using namespace std;#define maxn 10005struct Product{ int p, d;}prod[maxn];int n;int father[maxn];bool operator< (const Product &a, const Product &b){ return a.p > b.p;}int getanc(int a){ if (a <0) return a; if (a == father[a]) return a; return father[a] = getanc(father[a]);}bool ins(Product &a){ int temp = getanc(a.d -1); if (temp >=0) { father[temp] = getanc(temp -1); return true; } return false;}int main(){while (scanf("%d", &n) != EOF) { int t =0; for (int i=0; i < n; i++) { scanf("%d%d", ∏[i].p, ∏[i].d); if (t < prod[i].d) t = prod[i].d; } sort(prod, prod + n); for (int i =0; i < t; i++) father[i] = i; int ans =0; for (int i =0; i < n; i++) if (ins(prod[i])) ans += prod[i].p; printf("%dn", ans); } return 0;}
