You are running for a governor in a small city in Russia. You ran some polls and did some research, and for every person in the city you know whom he will vote for, and how much it will cost to bribe that person to vote for you instead of whomever he wants to vote for right now. You are curious, what is the smallest amount of money you need to spend on bribing to win the elections. To win elections you need to have strictly more votes than any other candidate.

Input

First line contains one integer n (1 ≤ n ≤ 105) — number of voters in the city. Each of the next n lines describes one voter and contains two integers ai and bi (0 ≤ ai ≤ 105; 0 ≤ bi ≤ 104) — number of the candidate that voter is going to vote for and amount of money you need to pay him to change his mind. You are the candidate 0 (so if a voter wants to vote for you, ai is equal to zero, in which case bi will also be equal to zero).

Output

Print one integer — smallest amount of money you need to spend to win the elections.

Examples

Input

5
1 2
1 2
1 2
2 1
0 0


Output

3


Input

4
1 2
1 2
2 1
0 0


Output

2


Input

1
100000 0


Output

0

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.Calendar;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.SortedSet;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;

/**
 * #
 * @author pttrung
 */
public class C_MemSQL2_Round2 {

    public static long MOD = 1000000007;  

    public static void main(String[] args) throws FileNotFoundException {
        // PrintWriter out = new PrintWriter(new FileOutputStream(new File(
        // "output.txt")));
        PrintWriter out = new PrintWriter(System.out);
        Scanner in = new Scanner(); 
        int n = in.nextInt();
        TreeMap<Integer, PriorityQueue<Integer>> map = new TreeMap();
        for(int i = 0; i < n; i++){
        	int a = in.nextInt();
        	int b = in.nextInt();
        	if(!map.containsKey(a)){
        		map.put(a, new PriorityQueue());
        	}
        	map.get(a).add(b);
        }
       
        int[][]data = new int[map.size() + (map.firstKey() != 0 ? 1 : 0)][];
       // System.out.println(data.length);
        int index = 0;
        for(int i : map.keySet()){
        	if(index == 0 && i != 0){
        		data[index] = new int[0];
        		index++;
        	}
        	data[index] = new int[map.get(i).size()];
        	for(int j = 0; j < data[index].length; j++){
        		data[index][j] = map.get(i).poll();
        		if(j > 0){
        			data[index][j] += data[index][j - 1];
        		}
        	}
        	index++;
        }
        int start = data[0].length;
        int end = n;
        int result = data[0].length == n ? 0 : Integer.MAX_VALUE;
        while(start < end){
        	int mid = (start + end)/2;
        	int a = cost(mid,  mid - data[0].length, data);
        	int b = cost(mid + 1, mid + 1 - data[0].length, data);
        	if(a < b){
        		end = mid;
        		result = Math.min(result, a);
        	}else{
        		start = mid + 1;
        		result = Math.min(result, b);
        	}
        }
        out.println(result);
        out.close();
    }
    static int cost(int mid, int need, int[][]data){
    	if(mid == 0){
    		return Integer.MAX_VALUE;
    	}
    	int result = 0;
    	PriorityQueue<Integer> q = new PriorityQueue<>();
    	for(int i = 1; i< data.length; i++){
    		
    		int start = 0;
    		
    		if(data[i].length >= mid){
    			int left = data[i].length - mid ;
    			
    			result += data[i][left];
    			start = left + 1;
    			need -=  left + 1;
    		}
    		for(int j = start; j < data[i].length; j++){
    			q.add(data[i][j] - (j > 0 ? data[i][j - 1] : 0));
    		}
    	}
    	while(need > 0){
    		result += q.poll();
    		need--;
    	}
    	return result;
    }
    
    

    public static int[] KMP(String val) {
        int i = 0;
        int j = -1;
        int[] result = new int[val.length() + 1];
        result[0] = -1;
        while (i < val.length()) {
            while (j >= 0 && val.charAt(j) != val.charAt(i)) {
                j = result[j];
            }
            j++;
            i++;
            result[i] = j;
        }
        return result;

    }

    public static boolean nextPer(int[] data) {
        int i = data.length - 1;
        while (i > 0 && data[i] < data[i - 1]) {
            i--;
        }
        if (i == 0) {
            return false;
        }
        int j = data.length - 1;
        while (data[j] < data[i - 1]) {
            j--;
        }
        int temp = data[i - 1];
        data[i - 1] = data[j];
        data[j] = temp;
        Arrays.sort(data, i, data.length);
        return true;
    }

    public static int digit(long n) {
        int result = 0;
        while (n > 0) {
            n /= 10;
            result++;
        }
        return result;
    }

    public static double dist(long a, long b, long x, long y) {
        double val = (b - a) * (b - a) + (x - y) * (x - y);
        val = Math.sqrt(val);
        double other = x * x + a * a;
        other = Math.sqrt(other);
        return val + other;



    }

    public static class Point implements Comparable<Point> {

        int x, y;

        public Point(int start, int end) {
            this.x = start;
            this.y = end;
        }

        @Override
        public int hashCode() {
            int hash = 5;
            hash = 47 * hash + this.x;
            hash = 47 * hash + this.y;
            return hash;
        }

        @Override
        public boolean equals(Object obj) {
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            final Point other = (Point) obj;
            if (this.x != other.x) {
                return false;
            }
            if (this.y != other.y) {
                return false;
            }
            return true;
        }

        @Override
        public int compareTo(Point o) {
            return Integer.compare(x, o.x);
        }
    }

    public static class FT {

        long[] data;

        FT(int n) {
            data = new long[n];
        }

        public void update(int index, long value) {
            while (index < data.length) {
                data[index] += value;
                index += (index & (-index));
            }
        }

        public long get(int index) {
            long result = 0;
            while (index > 0) {
                result += data[index];
                index -= (index & (-index));
            }
            return result;

        }
    }

    public static long gcd(long a, long b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }

    public static long pow(long a, long b) {
        if (b == 0) {
            return 1;
        }
        if (b == 1) {
            return a;
        }
        long val = pow(a, b / 2);
        if (b % 2 == 0) {
            return val * val % MOD;
        } else {
            return val * (val * a % MOD) % MOD;


        }
    }

    static class Scanner {

        BufferedReader br;
        StringTokenizer st;

        public Scanner() throws FileNotFoundException {
            // System.setOut(new PrintStream(new BufferedOutputStream(System.out), true));
            br = new BufferedReader(new InputStreamReader(System.in));
            //  br = new BufferedReader(new InputStreamReader(new FileInputStream(new File("input.txt"))));
        }

        public String next() {

            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception e) {
                    throw new RuntimeException();
                }
            }
            return st.nextToken();
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        public String nextLine() {
            st = null;
            try {
                return br.readLine();
            } catch (Exception e) {
                throw new RuntimeException();
            }
        }

        public boolean endLine() {
            try {
                String next = br.readLine();
                while (next != null && next.trim().isEmpty()) {
                    next = br.readLine();
                }
                if (next == null) {
                    return true;
                }
                st = new StringTokenizer(next);
                return st.hasMoreTokens();
            } catch (Exception e) {
                throw new RuntimeException();
            }
        }
    }
}
