Buggy python submission (verdict: Runtime Error):
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

N,Q = map(int,input().split())

MaxLength = N
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)

Fixed submission:
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

N,Q = map(int,input().split())

MaxLength = 2 * N
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)

Buggy python submission (verdict: Runtime Error):
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

MaxLength = 500001
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

N,Q = map(int,input().split())
c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)

Fixed submission:
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

N,Q = map(int,input().split())

MaxLength = 2 * N
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)

Buggy python submission (verdict: Runtime Error):
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

MaxLength = 5
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

N,Q = map(int,input().split())
c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)

Fixed submission:
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

N,Q = map(int,input().split())

MaxLength = 2 * N
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)

Buggy python submission (verdict: Runtime Error):
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

N,Q = map(int,input())
c = list(map(int,input().split()))

colors = {}
colorCount = []
cnt = 0
for elem in c:
    if elem not in colors:
        colors[elem] = 1
        cnt += 1
    colorCount.append(cnt)

for _ in range(Q):
    l,r = map(int,input().split())
    if l == 1:
        lColor = 0
    else:
        lColor = colorCount[l - 2]
    print(colorCount[r - 1] - lColor)

Fixed submission:
# Fast IO (only use in integer input)

import os,io
input=io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

# Fenwick Tree to Calculate Sum

N,Q = map(int,input().split())

MaxLength = 2 * N
FenwickTree = []

CurLen = MaxLength
while CurLen != 0:
    FenwickTree.append([0] * CurLen)
    CurLen //= 2

Depth = len(FenwickTree)

def addElem(n,index): # add n to an element in index
    for j in range(Depth):
        FenwickTree[j][index] += n
        index //= 2

def firstNSum(n): # Return the sum of the first n elements (0 to n-1)
    nCpy = n
    summ = 0
    depthCur = 0
    while nCpy != 0:
        if nCpy % 2 != 0:
            summ += FenwickTree[depthCur][nCpy - 1]
        nCpy //= 2
        depthCur += 1
    return summ

c = list(map(int,input().split()))
firstLocColor = [-1] * N
ans = [-1] * Q
queries = []
for i in range(Q):
    l,r = map(int,input().split())
    queries.append((l,r,i))
queries.sort(key = lambda x: x[1])
queryIndex = 0
for i in range(N):
    # Update the Fenwick tree to count ith element
    if firstLocColor[c[i] - 1] == -1:
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    else:
        addElem(-1,firstLocColor[c[i] - 1])
        addElem(1,i)
        firstLocColor[c[i] - 1] = i
    
    # get query
    while queryIndex < Q and queries[queryIndex][1] - 1 <= i:
        if queries[queryIndex][1] - 1 == i:
            ans[queries[queryIndex][2]] = firstNSum(queries[queryIndex][1]) - firstNSum(queries[queryIndex][0] - 1)
        queryIndex += 1

for elem in ans:
    print(elem)