/in/foo.c: In function 'main':
/in/foo.c:14:18: warning: left-hand operand of comma expression has no effect [-Wunused-value]
  for(a=0,c=1; a<9,c<10; a++,c++) {
                  ^
/in/foo.c:6:16: warning: unused variable 'f' [-Wunused-variable]
  int a,b=0,c,e,f,sum=0;
                ^
/in/foo.c:6:14: warning: unused variable 'e' [-Wunused-variable]
  int a,b=0,c,e,f,sum=0;
              ^