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;

fn main() {
    let n = read::<usize>();
    let a = read_vec::<usize>();
    let mut map: HashMap<usize, usize> = HashMap::new();
    for i in 0..n {
        let tmp = a[i];
        let entry = map.entry(tmp).or_insert(0);
        *entry += 1;
    }
    let q = read::<usize>();
    let mut v: Vec<Vec<usize>> = Vec::new();
    for _ in 0..q {
        let bc = read_vec::<usize>();
        v.push(bc);
    }
    let mut sum: usize = a.iter().sum();
    for i in 0..q {
        let bc = &v[i];
        let bentry = map.entry(bc[0]).or_insert(0);
        let tmp = *bentry;
        *bentry = 0;
        let centry = map.entry(bc[1]).or_insert(0);
        *centry += tmp;

        if bc[0] > bc[1] {
            let d = (bc[0] - bc[1]) * tmp;
            sum -= d;
        } else {
            let d = (bc[1] - bc[0]) * tmp;
            sum += d;
        }
        println!("{}", sum);
    }
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}