#include <cstdio>

/** Interface */

inline int readChar();
template <class T = int> inline T readInt(); 
template <class T> inline void writeInt( T x );
inline void writeChar( int x ); 
inline void writeWord( const char *s );
inline void flush();

/** Read */

static const int buf_size = 4096;

inline int getChar() {
  static char buf[buf_size];
  static int len = 0, pos = 0;
  if (pos == len)
    pos = 0, len = fread(buf, 1, buf_size, stdin);
  if (pos == len)
    return -1;
  return buf[pos++];
}

inline int readChar() {
  int c = getChar();
  while (c <= 32)
    c = getChar();
  return c;
}

template <class T>
inline T readInt() {
  int s = 1, c = readChar();
  T x = 0;
  if (c == '-')
    s = -1, c = getChar();
  while ('0' <= c && c <= '9')
    x = x * 10 + c - '0', c = getChar();
  return s == 1 ? x : -x;
}

/** Write */

static int write_pos = 0;
static char write_buf[buf_size];

inline void writeChar( int x ) {
  if (write_pos == buf_size)
    fwrite(write_buf, 1, buf_size, stdout), write_pos = 0;
  write_buf[write_pos++] = x;
}

inline void flush() {
  if (write_pos)
    fwrite(write_buf, 1, write_pos, stdout), write_pos = 0;
}

template <class T> 
inline void writeInt( T x ) {
  if (x < 0)
    writeChar('-'), x = -x;

  char s[24];
  int n = 0;
  while (x || !n)
    s[n++] = '0' + x % 10, x /= 10;
  while (n--)
    writeChar(s[n]);
}

inline void writeWord( const char *s ) {
  while (*s)
    writeChar(*s++);
}