Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline

n,m,q = map(int,input().split())
c=[[0 for i in range(n+1)] for j in range(n+1)]
x=[[0 for i in range(n+1)] for j in range(n+1)]
for i in range(m):
    l,r = map(int,input().split())
    x[l][r] += 1
for i in range(1,n+1):
    for j in range(1,n+1):
        c[i][j] = c[i][j-1] + x[i][j]
for i in range(q):
    p,q = map(int,input().split())
    sum = 0
    for j in range(p,q+1):
         sum+= c[j][q] - c[j][p-1]
    print(sum)


Fixed submission:
import sys
input = sys.stdin.readline

n,m,q = map(int,input().split())
c=[[0 for i in range(n+1)] for j in range(n+1)]
x=[[0 for i in range(n+1)] for j in range(n+1)]
for i in range(m):
    l,r = map(int,input().split())
    x[l][r] += 1
for i in range(1,n+1):
    for j in range(1,n+1):
        c[i][j] = c[i][j-1] + x[i][j]
for i in range(q):
    p,q = map(int,input().split())
    sum = 0
    for j in range(p,q+1):
         sum+= c[j][q] - c[j][p-1]
    print(sum)

Buggy python submission (verdict: Runtime Error):
import sys
import os
f = open("C:/Users/kazuki/Documents/python/import.txt","r")
sys.stdin = f
# -*- coding: utf-8 -*-
import itertools
import math
from collections import deque
from collections import defaultdict
from itertools import permutations
import heapq
import bisect
from scipy.sparse.csgraph import floyd_warshall as wf
from collections import Counter
from itertools import*
from bisect import bisect_left,bisect_right
from collections import Counter
inf = 10**10
input = sys.stdin.readline

n,m,q = map(int,input().split())
c=[[0 for i in range(n+1)] for j in range(n+1)]
x=[[0 for i in range(n+1)] for j in range(n+1)]
for i in range(m):
    l,r = map(int,input().split())
    x[l][r] += 1
for i in range(1,n+1):
    for j in range(1,n+1):
        c[i][j] = c[i][j-1] + x[i][j]
for i in range(q):
    p,q = map(int,input().split())
    sum = 0
    for j in range(p,q+1):
         sum+= c[j][q] - c[j][p-1]
    print(sum)

Fixed submission:
import sys
input = sys.stdin.readline

n,m,q = map(int,input().split())
c=[[0 for i in range(n+1)] for j in range(n+1)]
x=[[0 for i in range(n+1)] for j in range(n+1)]
for i in range(m):
    l,r = map(int,input().split())
    x[l][r] += 1
for i in range(1,n+1):
    for j in range(1,n+1):
        c[i][j] = c[i][j-1] + x[i][j]
for i in range(q):
    p,q = map(int,input().split())
    sum = 0
    for j in range(p,q+1):
         sum+= c[j][q] - c[j][p-1]
    print(sum)

Buggy python submission (verdict: Time Limit Exceeded):
n,m,q = map(int,input().split())
c=[[0 for i in range(n+1)] for j in range(n+1)]
x=[[0 for i in range(n+1)] for j in range(n+1)]
for i in range(m):
    l,r = map(int,input().split())
    x[l][r] += 1
for i in range(1,n+1):
    for j in range(1,n+1):
        c[i][j] = c[i][j-1] + x[i][j]
for i in range(q):
    p,q = map(int,input().split())
    sum = 0
    for j in range(p,q+1):
         sum+= c[j][q] - c[j][p-1]
    print(sum)


Fixed submission:
import sys
input = sys.stdin.readline

n,m,q = map(int,input().split())
c=[[0 for i in range(n+1)] for j in range(n+1)]
x=[[0 for i in range(n+1)] for j in range(n+1)]
for i in range(m):
    l,r = map(int,input().split())
    x[l][r] += 1
for i in range(1,n+1):
    for j in range(1,n+1):
        c[i][j] = c[i][j-1] + x[i][j]
for i in range(q):
    p,q = map(int,input().split())
    sum = 0
    for j in range(p,q+1):
         sum+= c[j][q] - c[j][p-1]
    print(sum)