how to access the element in an array in structure

[jinnejeevansai]

#include <stdio.h>
struct stack{
int n,,a[100];
}s;
int main()
{ int i;
scanf("%d",&s.n);
printf("%d",s.n);
for(i=0;i<3;i++)
{
scanf("%d",&s.a[i]);
printf("%d",s.a[i]);
}
return 0;
}
this program is not running why can't i access elements in this way directly.

[weaknessforcats]

It's nothing to do with accessing the array element. It has to do with those two commas in the struct. You can have only one comma. Two commas may be valid in other languages but not in C.C++.