/in/foo.cc: In function 'int main()':
/in/foo.cc:8:7: warning: statement has no effect [-Wunused-value]
  for(x;x!=1;)
       ^
/in/foo.cc:6:8: warning: unused variable 'a' [-Wunused-variable]
  int x,a=0,b=0;
        ^