foo.cc: In function 'void build()':
foo.cc:23:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d%d%d",&n,&m,&TIME,&MONEY);
 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:26:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d%d%d",&u,&v,&T,&M);
 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status

[Hydro](https://hydro.ac)提供评测服务