/in/foo.cc: In function 'int ins(int, int, int, int)':
/in/foo.cc:26:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int spfa()':
/in/foo.cc:45:5: error: expected ';' before '}' token
     }
     ^
/in/foo.cc: In function 'int mcf()':
/in/foo.cc:59:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^