I have a two-dimensional arrangement with the rand function in which it adds the total of rows but I do not know how to do it so that it also sums the total of columns

in row 16 is where I want to add the total of each column

include stdio.h >

include conio.h >

include stdlib.h >

include time.h >

int arr [16] [13], x, y, acu;

main ()

{

printf ("\ n"); printf ("vendor Vento Jetta Polo Teramont Beetle Golf Gol Passat Up! Tiguan Touareg TOTAL"); printf ("\ n");

srand(time(NULL));
for(x=0;x<15;x++)
for(y=1;y<12;y++)

arr[x][y]=1+rand()%9;


for(x=0;x<15;x++){

    acu=0;
    for(y=1;y<13;y++)
    acu=acu+arr[x][y];
    arr[x][12]=acu;
}

    //




    //
for(x=0;x<15;x++){
printf("\n");

for(y=1;y<13;y++)
printf("\t%d", arr[x][y]);

}     getch ();     return 0; }