# Calculate sum of boundary elements of a matrix…[Cprogm] FcukTheCode

Advika bought a cadbaury gems pocket for his friends. She opened the pocket and arranged the gems colour wise. After finishing the arrangement it looked like a matrix.

Now She wanted to calculate sum of boundary elements of a matrix.
If you help Advika, she will share chocolates with you.

``````Input:
The first input has two numbers r and c respectively.
Then r rows with c columns follow

Output:
print the single value representing sum of boundary elements of a Matrix.``````
```#include <stdio.h>
int main()
{
int r,c;
int arr[100][100],sum = 0,i,j;
scanf("%d %d",&r,&c);
for(i = 0;i < r;i++){
for(j=0;j < c;j++){
scanf("%d",&arr[i][j]);
}
}
for(i=0;i<r;i++){
for(j=0;j<c;j++){
if(i==0 || j==0 || i==r-1 || j==c-1){
sum+=arr[i][j];
}
}
}
//printf("Sum: ");
printf("%d",sum);
return 0;
}```

INPUT_1:
3  3
1  2  3
4  5  6
7  8  9

OUTPUT:
40

INPUT_2:
2  3
1  2  3
4  5  4

OUTPUT:
19

INPUT_3:
3  3
100  200  300
50  26  80
600  120  45

OUTPUT:
Sum: 1495

ILLUSTRATION: