mgo.cpp:3: error: 'sd' is not a namespace-name mgo.cpp:3: error: expected namespace-name before ';' token mgo.cpp:5: error: 'ifsream' does not name a type mgo.cpp:6: error: 'ofsream' does not name a type mgo.cpp: In function 'int main()': mgo.cpp:11: error: 'fin' was not declared in this scope mgo.cpp:48: error: 'fout' was not declared in this scope