/in/foo.cc: In function 'int main()':
/in/foo.cc:4:10: warning: unused variable 'b' [-Wunused-variable]
  int a=1,b=1,c=0,d=1,e,n,sum=0;
          ^
/in/foo.cc:4:18: warning: unused variable 'd' [-Wunused-variable]
  int a=1,b=1,c=0,d=1,e,n,sum=0;
                  ^