Problem:
Score : 400 points

Problem Statement

You have a sequence A composed of N positive integers: A_{1}, A_{2}, \cdots, A_{N}.

You will now successively do the following Q operations:

In the i-th operation, you replace every element whose value is B_{i} with C_{i}.

For each i (1 \leq i \leq Q), find S_{i}: the sum of all elements in A just after the i-th operation.

Constraints

All values in input are integers.

1 \leq N, Q, A_{i}, B_{i}, C_{i} \leq 10^{5}

B_{i} \neq C_{i}

Input

Input is given from Standard Input in the following format:

N
A_{1} A_{2} \cdots A_{N}
Q
B_{1} C_{1}
B_{2} C_{2}
\vdots
B_{Q} C_{Q}

Output

Print Q integers S_{i} to Standard Output in the following format:

S_{1}
S_{2}
\vdots
S_{Q}

Note that S_{i} may not fit into a 32-bit integer.

Sample Input 1

4
1 2 3 4
3
1 2
3 4
2 4

Sample Output 1

11
12
16

Initially, the sequence A is 1,2,3,4.

After each operation, it becomes the following:

2, 2, 3, 4

2, 2, 4, 4

4, 4, 4, 4

Sample Input 2

4
1 1 1 1
3
1 2
2 1
3 5

Sample Output 2

8
4
4

Note that the sequence A may not contain an element whose value is B_{i}.

Sample Input 3

2
1 2
3
1 100
2 100
100 1000

Sample Output 3

102
200
2000

Solution in Java (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) {

        IO io = new IO();

        int n = io.nextInt();
        int[] a = io.nIntA(n);

        Map<Integer, Long> map = new HashMap<>();
        long sum = 0;
        
        for (int i = 0; i < n; i++) {
            long v = map.getOrDefault(a[i], 0L);
            map.put(a[i], v + 1L);
            sum += a[i];
        }

        int q = io.nextInt();
        for (int i = 0; i < q; i++) {
            int b = io.nextInt();
            int c = io.nextInt();

            if (map.containsKey(b)) {

                long count = map.get(b);
                long sumb = count * b;
                long sumc = count * c;

                sum -= sumb;
                sum += sumc;


                if (map.containsKey(c)) {
                    map.put(c, map.get(c) + count);
                } else {
                    map.put(c, count);
                }
                map.remove(b);
                io.write(sum);
            } else {
                io.write(sum);
            }
        }
    }
    
    static class IO {
        BufferedWriter bw;
        BufferedReader br;
        StringTokenizer st;

        public IO() {
            br = new BufferedReader(new InputStreamReader(System.in));
            bw = new BufferedWriter(new OutputStreamWriter(System.out));
        }

        public void write(String s) {
            try {
                StringBuilder sb = new StringBuilder();
                sb.append(s);
                sb.append("\n");
                bw.write(sb.toString());
                bw.flush();
            } catch(Exception e) {
                e.printStackTrace();
            }  
        }

        public void write(long value) {
            try {
                StringBuilder sb = new StringBuilder();
                sb.append(value);
                sb.append("\n");
                bw.write(sb.toString());
                bw.flush();
            } catch(Exception e) {
                e.printStackTrace();
            }
        }

        public void write(int value) {
            try {
                StringBuilder sb = new StringBuilder();
                sb.append(value);
                sb.append("\n");
                bw.write(sb.toString());
                bw.flush();
            } catch(Exception e) {
                e.printStackTrace();
            }
        }

        public void write(boolean b, String truev, String falsv) {
            try {
                StringBuilder sb = new StringBuilder();
                sb.append(b ? truev : falsv);
                sb.append("\n");
                bw.write(sb.toString());
                bw.flush();
            } catch(Exception e) {
                e.printStackTrace();
            }
        }

        public void write(int[] a, char sep) {
            try {
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < a.length; i++) {
                   sb.append(a[i]);
                   sb.append(sep);
                }
                sb.append("\n");
                bw.write(sb.toString());
                bw.flush();
            } catch(Exception e) {
                e.printStackTrace();
            }
        }

        public void write(long[] a, char sep) {
            try {
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < a.length; i++) {
                   sb.append(a[i]);
                   sb.append(sep);
                }
                sb.append("\n");
                bw.write(sb.toString());
                bw.flush();
            } catch(Exception e) {
                e.printStackTrace();
            }
        }
 
        public String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        public int nextInt() {
            return Integer.parseInt(next());
        }

        public int[] nIntA(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }

        public long[] nLongA(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextLong();
            }
            return a;
        }

        public double[] nDoubleA(int n) {
            double[] a = new double[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextDouble();
            }
            return a;
        }
 
        public long nextLong() {
            return Long.parseLong(next());
        }
 
        public double nextDouble() {
            return Double.parseDouble(next());
        }
 
        public String nextLine() {
            String str = "";
            try{
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}