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Time Limit: 2 s Memory Limit: 256 MB Total points: 100

#22493. Book Club

Statistics

Bessie is looking for cows to join her book club. While the herd has $N$ ($2 \le N \le 50,000$) cows conveniently numbered 1..$N$, she wants only the most discerning and social cows for her book club.

Thus, like a dating service, she has created a questionnaire and asked each of the $N$ cows to complete its $NQ$ ($1 \le NQ \le 50$) questions (named $R_{1}$..$R_{NQ}$). These are questions like "How much do you enjoy reading science fiction?" and each answer is an integer in the range 1..5.

Your job is to tabulate the questionnaire's results and answer a simple question like: "How many cows answered 2 to question 3, 4 to question 7, and also 1 to question 8?" The question has $P$ parts ($1 \le P \le 10$), and each part has $Qj$ ($1 \le Qj \le NQ$) and $Aj$ ($1 \le Aj \le 5$), respectively the question number and the required answer. Your program prints a single integer that is the total number of cows that answered $Aj$ to $Qj$ for j in the range 1..$P$.

Consider a small herd of just 4 cows and a small questionnaire of just 5 questions; the responses are:

Cow     Question ID   1  2  3  4  5
1    1  1  1  1  1
2    1  2  3  4  5
3    1  2  1  2  3
4    2  1  1  2  2

If the tabulation question was "How many cows answered 2 to question 1 and 1 to question 2?" the answer would be 1 (just cow #4). If the tabulation question was "How many cows answered 1 to question 1 and 1 to question 3?" the answer would be 2 (cows 1 and 3).

Input

  • Line 1: Three space-separated integers: $N$, $NQ$, and $P$
  • Lines 2..$N$+1: Line i+1 contains $NQ$ space-separated integers that are the response to the questions for cow i: $R_{1}$..$R_{NQ}$
  • Lines $N$+2..$N$+1+$P$: Line j+$N$+1 contains two space-separated integers: $Qj$ and $Aj$

Output

  • Line 1: A single integer that is the number of cows that meet all of Bessie's criteria

Examples

Input 1

4 5 2
1 1 1 1 1
1 2 3 4 5
1 2 1 2 3
2 1 1 2 2
1 1
3 1

Output 1

2

Problem credits: Rob Kolstad, 2010

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