#include <bits/stdc++.h>   using namespace std;   template <typename T1, typename T2>   inline void chkmin(T1 &x, T2 y) {     if (x > y) x = y;   }   template <typename T1, typename T2>   inline void chkmax(T1 &x, T2 y) {     if (x < y) x = y;   }   inline int readChar();   template <class T = int>   inline T readInt();   template <class T>   inline void writeInt(T x, char end = 0);   inline void writeChar(int x);   inline void writeWord(const char *s);   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;   }   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;   }   template <class T>   inline void writeInt(T x, char end) {     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]);     if (end) writeChar(end);   }   inline void writeWord(const char *s) {     while (*s) writeChar(*s++);   }   struct Flusher {     ~Flusher() {       if (write_pos) fwrite(write_buf, 1, write_pos, stdout), write_pos = 0;     }   } flusher;   const string FILENAME =  input ;   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n;     cin >> n;     if (n & 1) {       cout << (n / 2 + 1) * (n / 2 + 1) << endl;     } else {       cout << (n / 2 + 1) * (n / 2) << endl;     }     return 0;   }   