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 Rust (1.42.0) (judge verdict: Accepted)

use std::collections::HashMap;
use std::error::Error;
use std::io;

pub fn main() {
    if let Err(_e) = run() {
        panic!("failed.");
    }
}

fn run() -> Result<(), Box<dyn Error>> {
    let mut input = String::new();
    io::stdin().read_line(&mut input)?;
    input.clear();
    io::stdin().read_line(&mut input)?;
    let a_s: Vec<i32> = input
        .trim()
        .split_whitespace()
        .map(|s| s.parse::<i32>().unwrap())
        .collect();
    input.clear();

    let mut map: HashMap<i32, i32> = HashMap::new();

    let mut result = 0 as i64;
    for x in a_s {
        result += x as i64;
        let count = map.entry(x).or_insert(0);
        *count += 1;
    }

    io::stdin().read_line(&mut input)?;
    let q = input.trim().parse::<i32>()?;
    input.clear();
    for _ in 0..q {
        io::stdin().read_line(&mut input)?;
        let b_c: Vec<i32> = input
            .trim()
            .split_whitespace()
            .map(|s| s.parse::<i32>().unwrap())
            .collect();
        let b = b_c[0];
        let c = b_c[1];
        input.clear();
        let temp = c - b;
        if let Some(&count) = map.get(&b) {
            result += temp as i64 * count as i64;
            *map.entry(c).or_insert(0) += count;
        }
        map.remove(&b);
        println!("{}", result);
    }

    Ok(())
}