PROGRAMMING:Triple table subtraction
Two sparse matrices A and B of the same order are represented by triples respectively. The program is written to find C = A-B, and C is also represented by triples.
###Input format:
The first line is two positive integers m and n not more than 1000, which represent the number of non-zero elements of matrix A and B, that is, the length of triple table of a and B. The next M rows represent the node information of M triples of matrix a respectively, and 3 integers in each row represent the row number, column number and value of each triplet node. The next n rows represent the node information of N triples of matrix B, and 3 integers in each row represent the row number, column number and value of each triplet node.
###Output format:
Output the triple table of matrix C, each triple node has a row, the elements in the same row are separated by spaces, and there is no space after the last element in each row.
###Input example:
```in
3 2
1 2 3
2 1 8
2 3 6
1 2 1
2 1 3
```
###Output example:
```out
1 2 2
2 1 5
2 3 6
```
answer：If there is no answer, please comment
###Input format:
The first line is two positive integers m and n not more than 1000, which represent the number of non-zero elements of matrix A and B, that is, the length of triple table of a and B. The next M rows represent the node information of M triples of matrix a respectively, and 3 integers in each row represent the row number, column number and value of each triplet node. The next n rows represent the node information of N triples of matrix B, and 3 integers in each row represent the row number, column number and value of each triplet node.
###Output format:
Output the triple table of matrix C, each triple node has a row, the elements in the same row are separated by spaces, and there is no space after the last element in each row.
###Input example:
```in
3 2
1 2 3
2 1 8
2 3 6
1 2 1
2 1 3
```
###Output example:
```out
1 2 2
2 1 5
2 3 6
```
answer：If there is no answer, please comment