[C++] Varför får jag segfault? (löst)

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv)
{
	if(argc < 1)
		return 1;
	if(!atoi(argv[1]))
		printf("Error.");
	else printf("Success.");
	return 0;
}

(gdb) backtrace
#0  0x00000034cd239f54 in ____strtoll_l_internal () from /lib64/libc.so.6
#1  0x00000034cd236fa0 in atoi () from /lib64/libc.so.6
#2  0x000000000040061b in main ()