Buggy python submission (verdict: Time Limit Exceeded):
import sys
import numpy as np

# 実行環境(0:vscode, 1:atcoder)
MODE = 1

# 入力の次元
DIMENSION = 2

# int型に変換
INT_TYPE = 1

if not (MODE):
    with open("input.txt", "r") as f:
        s = f.read()
else:
    s = sys.stdin.read()

if DIMENSION == 0:
    if INT_TYPE == 1:
        s = int(s)
elif DIMENSION == 1:
    if INT_TYPE == 0:
        s = s.split()
    elif INT_TYPE == 1:
        s = [int(x) for x in s.split()]
elif DIMENSION == 2:
    if INT_TYPE == 0:
        s = [x.split() for x in s.splitlines()]
    elif INT_TYPE == 1:
        s = [[int(y) for y in x.split()] for x in s.splitlines()]

N = s[0][0]
A = np.array(s[1])
Q = s[2][0]
BC = np.array(s[3:])
B = BC[:, 0]
C = BC[:, 1]

A_sum = np.sum(A)

D = np.array([np.count_nonzero(A == i) for i in range(100001)])
for i in range(Q):
    b = B[i]
    c = C[i]
    A_sum += D[b] * (c - b)
    print(A_sum)
    D[c] += D[b]
    D[b] = 0


Fixed submission:
import sys
import numpy as np
from collections import Counter

# 実行環境(0:vscode, 1:atcoder)
MODE = 1

# 入力の次元
DIMENSION = 2

# int型に変換
INT_TYPE = 1

if not (MODE):
    with open("input.txt", "r") as f:
        s = f.read()
else:
    s = sys.stdin.read()

if DIMENSION == 0:
    if INT_TYPE == 1:
        s = int(s)
elif DIMENSION == 1:
    if INT_TYPE == 0:
        s = s.split()
    elif INT_TYPE == 1:
        s = [int(x) for x in s.split()]
elif DIMENSION == 2:
    if INT_TYPE == 0:
        s = [x.split() for x in s.splitlines()]
    elif INT_TYPE == 1:
        s = [[int(y) for y in x.split()] for x in s.splitlines()]

N = s[0][0]
A = np.array(s[1])
Q = s[2][0]
BC = np.array(s[3:])
B = BC[:, 0]
C = BC[:, 1]

A_sum = np.sum(A)

D = Counter(A)

for i in range(Q):
    b = B[i]
    c = C[i]
    A_sum += D[b] * (c - b)
    print(A_sum)
    D[c] += D[b]
    D[b] = 0

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import numpy as np

# 実行環境(0:vscode, 1:atcoder)
MODE = 1

# 入力の次元
DIMENSION = 2

# int型に変換
INT_TYPE = 1

if not (MODE):
    with open("input.txt", "r") as f:
        s = f.read()
else:
    s = sys.stdin.read()

if DIMENSION == 0:
    if INT_TYPE == 1:
        s = int(s)
elif DIMENSION == 1:
    if INT_TYPE == 0:
        s = s.split()
    elif INT_TYPE == 1:
        s = [int(x) for x in s.split()]
elif DIMENSION == 2:
    if INT_TYPE == 0:
        s = [x.split() for x in s.splitlines()]
    elif INT_TYPE == 1:
        s = [[int(y) for y in x.split()] for x in s.splitlines()]

N = s[0][0]
A = np.array(s[1])
Q = s[2][0]
BC = np.array(s[3:])
B = BC[:, 0]
C = BC[:, 1]

A_sum = np.sum(A)

D = np.zeros(100001).astype(np.uint32)
D = np.array([np.count_nonzero(A == i) for i in range(100001)])
for i in range(Q):
    b = B[i]
    c = C[i]
    A_sum += D[b] * (c - b)
    print(A_sum)
    D[c] += D[b]
    D[b] = 0


Fixed submission:
import sys
import numpy as np
from collections import Counter

# 実行環境(0:vscode, 1:atcoder)
MODE = 1

# 入力の次元
DIMENSION = 2

# int型に変換
INT_TYPE = 1

if not (MODE):
    with open("input.txt", "r") as f:
        s = f.read()
else:
    s = sys.stdin.read()

if DIMENSION == 0:
    if INT_TYPE == 1:
        s = int(s)
elif DIMENSION == 1:
    if INT_TYPE == 0:
        s = s.split()
    elif INT_TYPE == 1:
        s = [int(x) for x in s.split()]
elif DIMENSION == 2:
    if INT_TYPE == 0:
        s = [x.split() for x in s.splitlines()]
    elif INT_TYPE == 1:
        s = [[int(y) for y in x.split()] for x in s.splitlines()]

N = s[0][0]
A = np.array(s[1])
Q = s[2][0]
BC = np.array(s[3:])
B = BC[:, 0]
C = BC[:, 1]

A_sum = np.sum(A)

D = Counter(A)

for i in range(Q):
    b = B[i]
    c = C[i]
    A_sum += D[b] * (c - b)
    print(A_sum)
    D[c] += D[b]
    D[b] = 0