Problem:
Score : 200 points

Problem Statement

You are visiting a large electronics store to buy a refrigerator and a microwave.

The store sells A kinds of refrigerators and B kinds of microwaves. The i-th refrigerator ( 1 \le i \le A ) is sold at a_i yen (the currency of Japan), and the j-th microwave ( 1 \le j \le B ) is sold at b_j yen.

You have M discount tickets. With the i-th ticket ( 1 \le i \le M ), you can get a discount of c_i yen from the total price when buying the x_i-th refrigerator and the y_i-th microwave together. Only one ticket can be used at a time.

You are planning to buy one refrigerator and one microwave. Find the minimum amount of money required.

Constraints

All values in input are integers.

1 \le A \le 10^5

1 \le B \le 10^5

1 \le M \le 10^5

1 \le a_i , b_i , c_i \le 10^5

1 \le x_i \le A

1 \le y_i \le B

c_i \le a_{x_i} + b_{y_i}

Input

Input is given from Standard Input in the following format:

A B M
a_1 a_2 ... a_A
b_1 b_2 ... b_B
x_1 y_1 c_1
\vdots
x_M y_M c_M

Output

Print the answer.

Sample Input 1

2 3 1
3 3
3 3 3
1 2 1

Sample Output 1

5

With the ticket, you can get the 1-st refrigerator and the 2-nd microwave for 3+3-1=5 yen.

Sample Input 2

1 1 2
10
10
1 1 5
1 1 10

Sample Output 2

10

Note that you cannot use more than one ticket at a time.

Sample Input 3

2 2 1
3 5
3 5
2 2 2

Sample Output 3

6

You can get the 1-st refrigerator and the 1-st microwave for 6 yen, which is the minimum amount to pay in this case.
Note that using a ticket is optional.

Solution in C (GCC 5.4.1) (judge verdict: Runtime Error)

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
	int a = 0;
	int b = 0;
	int coupon_num = 0;
	char dummy;
	int i = 0;

	/* input each num */
	scanf("%d%c%d%c%d%c", &a, &dummy, &b, &dummy, &coupon_num, &dummy);

	char a_string[a];
	int a_price[a];
	char b_string[b];
	int b_price[b];
	int coupon_array[3][coupon_num];

	scanf("%[^\n]%c", a_string, &dummy);

	/* reshape string to num*/
	for (i = 0; i < a; i++) {
		a_price[i] = atoi(&a_string[i]);
	}

	scanf("%[^\n]%c", b_string, &dummy);
	for (i = 0; i < b; i++) {
		b_price[i] = atoi(&b_string[i]);
	}

	for (i = 0; i < coupon_num; i++) {
		scanf("%d%c%d%c%d%c", &coupon_array[0][i], &dummy, &coupon_array[1][i], &dummy, &coupon_array[2][i], &dummy);
	}

	/* calc min price */
	int min_price = 0;
	int temp = 0;

	min_price = a_price[coupon_array[0][0]] + b_price[coupon_array[1][0]] - coupon_array[2][0];
	if (coupon_num > 1) {
		for (i = 1; i < coupon_num; i++) {
			temp = a_price[coupon_array[0][i]] + b_price[coupon_array[1][i]] - coupon_array[2][i];

			if (temp < min_price) temp = min_price;
		}
	}

	printf("%d\n", min_price);

	return 0;
}