What is the output of this program? #include #include int main() { int fd, count; char ch; fd = open("demo.txt",O_RDWR|O_CREAT); write(fd,"s",1); lseek(fd,0,SEEK_SET); write(fd,"d",1); lseek(fd,0,0); read(fd,&ch,1); printf("%cn",ch); return 0; }