foo.cpp: In function 'int main()':
foo.cpp:5:11: warning: variable 'c' set but not used [-Wunused-but-set-variable]
  int a[8],c=0,d,e,f;
           ^
foo.cpp:5:15: warning: unused variable 'd' [-Wunused-variable]
  int a[8],c=0,d,e,f;
               ^