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.math.BigInteger;
import java.util.*;
import java.util.stream.Collectors;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    Map<Long, Long> map = new HashMap<>();
    long result = 0L;
    for (int i = 0; i < n; i++) {
      long a = sc.nextLong();
      result += a;
      Long aLong = map.get(a);
      if (aLong == null) {
        aLong = 0L;
      }
      map.put(a, aLong + 1);
    }
    int q = sc.nextInt();
    for (int i = 0; i < q; i++) {
      long b = sc.nextLong();
      long c = sc.nextLong();
      Long aCount = map.get(b);
      if (aCount != null) {
        Long cCount = map.get(c);
        if (cCount == null) {
          cCount = 0L;
        }
        map.put(c, cCount + aCount);
        map.put(b, 0L);
        
        result += (c - b) * aCount;
      }
      System.out.println(result);
    }
  }
}