/in/foo.cc:72:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:77:20: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[10]' [-Wformat=]
      scanf("%s",&op);
                    ^

FormatError('config file not found',)