? occurs after output ??

By: mohd.r*** On: Sat Nov 28 00:27:40 IST 2015     0 0 0	0
#include<stdio.h> #include<conio.h> main(){ char a1[7]="strings"; char a2[6]="string"; printf("%s\n",a1); printf("%s\n",a2); getch(); return 0; } output: strings? string	0