Problem:
Score: 400 points

Problem Statement

In Takahashi Kingdom, there is a east-west railroad and N cities along it, numbered 1, 2, 3, ..., N from west to east.
A company called AtCoder Express possesses M trains, and the train i runs from City L_i to City R_i (it is possible that L_i = R_i).
Takahashi the king is interested in the following Q matters:

The number of the trains that runs strictly within the section from City p_i to City q_i, that is, the number of trains j such that p_i \leq L_j and R_j \leq q_i.

Although he is genius, this is too much data to process by himself. Find the answer for each of these Q queries to help him.

Constraints

N is an integer between 1 and 500 (inclusive).

M is an integer between 1 and 200 \ 000 (inclusive).

Q is an integer between 1 and 100 \ 000 (inclusive).

1 \leq L_i \leq R_i \leq N (1 \leq i \leq M)

1 \leq p_i \leq q_i \leq N (1 \leq i \leq Q)

Input

Input is given from Standard Input in the following format:

N M Q
L_1 R_1
L_2 R_2
:
L_M R_M
p_1 q_1
p_2 q_2
:
p_Q q_Q

Output

Print Q lines. The i-th line should contain the number of the trains that runs strictly within the section from City p_i to City q_i.

Sample Input 1

2 3 1
1 1
1 2
2 2
1 2

Sample Output 1

3

As all the trains runs within the section from City 1 to City 2, the answer to the only query is 3.

Sample Input 2

10 3 2
1 5
2 8
7 10
1 7
3 10

Sample Output 2

1
1

The first query is on the section from City 1 to 7. There is only one train that runs strictly within that section: Train 1.
The second query is on the section from City 3 to 10. There is only one train that runs strictly within that section: Train 3.

Sample Input 3

10 10 10
1 6
2 9
4 5
4 7
4 7
5 8
6 6
6 7
7 9
10 10
1 8
1 9
1 10
2 8
2 9
2 10
3 8
3 9
3 10
1 10

Sample Output 3

7
9
10
6
8
9
6
7
8
10

Solution in Python (3.4.3) (judge verdict: Wrong Answer)


def f(h,w,a):
    da = [[0]*w for _ in range(h)]
    da[0][0] = a[0][0]
    for i in range(1, w):
        da[0][i] = da[0][i-1] + a[0][i]
    for i in range(1, h):
        cnt_w = 0
        for j in range(w):
            cnt_w += a[i][j]
            da[i][j] = da[i-1][j] + cnt_w
    return da

def Calc(p,q,x,y, da):
    if p>x  or q>y:
        return 0
    if p==0 or q==0:
        return da[x][y]
    if p==0:
        return da[x][y] - da[x][q-1]
    if q==0:
        return da[x][y] - da[p-1][y]
    return da[x][y] - da[x][q-1] - da[p-1][y] + da[p-1][q-1]

N,M,Q = map(int,input().split())
t = [[0]*(N+1) for _ in range(N+1)]
for _ in range(M):
    l,r = map(int,input().split())
    t[l][r] += 1

d = f(N,N,t)
query = []
for _ in range(Q):
    p,q = map(int,input().split())
    p -= 1
    q -= 1
    print(Calc(p,p,q,q,d))