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 *AB;
int *A,*B,*C;

int an,bn,mn;


void main(void){
    int i,j;
    int sp;

    scanf("%d%d%d",&an,&bn,&mn);
    
    if((AB = (int*)malloc(sizeof(int)*an*bn)) == NULL){
        exit(1);
    }
    if((A = (int*)malloc(sizeof(int)*an)) == NULL){
        exit(1);
    }
    if((B = (int*)malloc(sizeof(int)*bn)) == NULL){
        exit(1);
    }
    if((C = (int*)malloc(sizeof(int)*an*bn)) == NULL){
        exit(1);
    }

    for(i = 0;i < an;i++){
        scanf("%d",&(A[i]));
    }
    for(i = 0;i < bn;i++){
        scanf("%d",&(B[i]));
    }


    for(i = 0;i < an;i++){
        for(j = 0;j < bn;j++){
            AB[i*(bn-1)+i+j] = A[i] + B[j];
        }
    }

    for(i = 0;i < an*bn;i++){
        C[i] = 0;
    }

    for(i = 0;i < mn;i++){
        int x,y,c;
        scanf("%d%d%d",&x,&y,&c);
        if(C[x*(y-1)+x+y] <= c){
            C[x*(y-1)+x+y] = c;
        }
    }

    sp = AB[0] - C[0];
    for(i = 0;i < an;i++){
        for(j = 0;j < bn;j++){
            if(AB[i*(j-1)+i+j] - C[i*(j-1)+i+j] <= sp){
                sp = AB[i*(j-1)+i+j] - C[i*(j-1)+i+j];
            }
        }
    }

    printf("%d",sp);

    free(AB);
    free(A);
    free(B);
    free(C);
    return;
}