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::io::*;
use std::str::FromStr;
use std::collections::BTreeMap;

fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("faild to read char") as char)
        .take_while(|c| !c.is_whitespace())
        .collect();
    token
        .parse()
        .ok()
        .expect("faild to parse token")
}

fn main(){
    let n: usize = read();
    let mut a: BTreeMap<u64, u64> = BTreeMap::new();

    for _ in 0..n {
        let b: u64 = read();
        match a.get_mut(&b) {
            Some(c) => { *c += 1; },
            None => { a.insert(b, 1); },
        }
    }

    let mut sum = (&a).into_iter().fold(0, |b, (c, d)| b + c * d);

    let q: usize = read();
    for _ in 0..q {
        let b: u64 = read();
        let c: u64 = read();
        let val = match a.get(&b) {
            Some(d) => d.clone(),
            None => {
                println!("{}", sum);
                continue;
            }
        };
        sum += c * val;
        sum -= b * val;
        println!("{}", sum);

        match a.get_mut(&c) {
            Some(d) => {
                *d += val;
            },
            None => {
                a.insert(c, val);
            }
        }
        a.remove(&b);
    }
}