Problem:
Score : 100 points

Problem Statement

In K-city, there are n streets running east-west, and m streets running north-south. Each street running east-west and each street running north-south cross each other. We will call the smallest area that is surrounded by four streets a block. How many blocks there are in K-city?

Constraints

2 ≤ n, m ≤ 100

Input

Input is given from Standard Input in the following format:

n m

Output

Print the number of blocks in K-city.

Sample Input 1

3 4

Sample Output 1

6

There are six blocks, as shown below:

Sample Input 2

2 2

Sample Output 2

1

There are one block, as shown below:

Solution in C (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>

#define BUF_SIZE 102
int main(void) {
  char line[BUF_SIZE];
  FILE *fp;
  fp = stdin;
  if(!fgets(line, BUF_SIZE, fp)) return 0;
  size_t len = strlen(line);
  if(line[len-1] == '\n') {
    len--;
  }
  printf("%c%d%c\n", line[0], (int)len, line[len-1]);

  return 0;
}