/in/foo.cc: In function 'int main()':
/in/foo.cc:11:6: warning: unused variable 'a' [-Wunused-variable]
   11 |  int a[50][2];
      |      ^
/in/foo.cc:13:6: warning: unused variable 'i' [-Wunused-variable]
   13 |  int i=0;
      |      ^