/in/foo.cc: In function 'int main()':
/in/foo.cc:7:32: error: unable to find string literal operator 'operator""a' with 'const char [3]', 'long unsigned int' arguments
  cout<<fixed<<setprecision(2)<<"C="a+b;
                                ^~~~~
/in/foo.cc:8:33: error: unable to find string literal operator 'operator""a' with 'const char [3]', 'long unsigned int' arguments
   cout<<fixed<<setprecision(2)<<"S="a*b;
                                 ^~~~~