Program terminated with signal SIGABRT, Aborted.
#0  0x00007f81762c004f in raise () from /usr/lib/libc.so.6
(gdb) bt
#0  0x00007f81762c004f in raise () from /usr/lib/libc.so.6
#1  0x00007f81762c147a in abort () from /usr/lib/libc.so.6
#2  0x00007f81762fdc50 in __libc_message () from /usr/lib/libc.so.6
#3  0x00007f8176303fe6 in malloc_printerr () from /usr/lib/libc.so.6
#4  0x00007f81763047de in _int_free () from /usr/lib/libc.so.6
#5  0x0000000000403a26 in ?? ()
#6  0x0000000000403ff9 in ?? ()
#7  0x000000000040358b in ?? ()
#8  0x00007f81762ad291 in __libc_start_main () from /usr/lib/libc.so.6
#9  0x00000000004038da in ?? ()