/in/foo.cc: In function 'void print(long long int)':
/in/foo.cc:46:28: warning: 'lasttail' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d %d",lasttail,m);
                            ^
/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status