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 11.0.6) (judge verdict: Accepted)

import java.util.*;
import java.io.*;
public class Main{
   public static void main(String[] main) throws Exception{
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st = new StringTokenizer(br.readLine());
      PrintWriter out = new PrintWriter(System.out);
      int n = Integer.parseInt(st.nextToken());
      st = new StringTokenizer(br.readLine());
      int[] a = new int[n];
      long sum = 0;
      HashMap<Integer,Long> freq = new HashMap<Integer,Long>();
      for(int i = 0; i < n; i++) {
    	  a[i] = Integer.parseInt(st.nextToken());
    	  sum += a[i];
    	  if(freq.keySet().contains(a[i]))
    		  freq.put(a[i],freq.get(a[i])+1);
    	  else
    		  freq.put(a[i],(long)1);
      }
      st = new StringTokenizer(br.readLine());
      int q = Integer.parseInt(st.nextToken());
      for(int i = 0; i < q; i++) {
          st = new StringTokenizer(br.readLine());
          int b = Integer.parseInt(st.nextToken());
          int c = Integer.parseInt(st.nextToken());
    	  if(freq.keySet().contains(b)) {
    		  sum += freq.get(b)*(c-b);
    		  if(freq.keySet().contains(c)) {
    			  freq.put(c, freq.get(c) + freq.get(b));
    		  }
    		  else
    			  freq.put(c,freq.get(b));
              freq.remove(b);
    	  }
    	  out.println(sum);
      }
      out.close();
   }
}