/in/foo.cc: In function 'int main()':
/in/foo.cc:6:10: warning: right operand of comma operator has no effect [-Wunused-value]
  cin>>L,d;
          ^
/in/foo.cc:11:28: error: 'setrecision' was not declared in this scope
  cout<<fixed<<setrecision(6)<<a;
                            ^