#include <stdio.h>

int main(void) {

  int i, j, k;
  int sum1 = 0.0, sum2 = 0, sum3 = 0, *pa;
  int a[2][3] = {{1, 2, 3}, {4, 5, 6}};

  for (i = 0; i < 2; i++)
    for (j = 0; j < 3; j++)
      sum1 += a[i][j];  

  for (k = 0; k < 2 * 3; k++)
    sum2 += *(&a[0][0] + k);  

  for (i = 0;  i < 2; i++){
    pa = *(&a[0] + i);
    for (j = 0; j < 3; j++)
      sum3 += *(pa + j);  
  }  

  printf("First method:  the sum is: %d\n", sum1);
  printf("Second method: The sum is: %d\n", sum2);
  printf("Third method: The sum is: %d\n", sum3);
  
  return 0;
}