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: Wrong Answer)

import java.util.HashMap;
import java.util.Scanner;
class Main{
    static long sum = 0;
    static Scanner scan = new Scanner(System.in);
    public static void main(String[] args) {
        int N = scan.nextInt();
        int[] arr = new int[N];
        takeInput(arr);
        int Q = scan.nextInt();
        for(int i = 0; i < arr.length; i++) {
            sum += arr[i];
        }

        HashMap<Integer, Integer> fmap = new HashMap<>();
        for(int i = 0; i < arr.length; i++) {
            if(fmap.containsKey(arr[i])) {
                int ov = fmap.get(arr[i]);
                ov = ov + 1;
                fmap.put(arr[i], ov);
            }else {
                fmap.put(arr[i], 1);
            }
        }
        while(Q > 0) {
            int A = scan.nextInt();
            int B = scan.nextInt();
            System.out.println(sumAfterOp(arr, A, B, fmap));
            Q--;
        }
    }

    private static void takeInput(int[] arr) {
        for(int i = 0; i < arr.length; i++) {
            arr[i] = scan.nextInt();
        }
    }

    private static long sumAfterOp(int[] arr, int A, int B, HashMap<Integer, Integer> fmap) {
        if(fmap.containsKey(A)) {
            int A_count = fmap.get(A);
            fmap.put(A, 0);
            sum -= A_count * A;
            if(fmap.containsKey(B)){
                fmap.put(B, fmap.get(B) + A_count);
            }else {
                fmap.put(B, A_count);
            }
            sum += A_count * B;
        }
        return sum;
    }
}