#codeifyoucansolve
C programming :
getchar_unlocked();
: This reads a charchater from stdin.
when there is no thread safety required but speed is.
Program :

#include<stdio.h>

int main()
{
  char ch;
  ch     =       getchar_unlocked();
  printf("%c\n",ch);
  return 0;
}

http://ideone.com/zABJQ0