import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum MAX_N = 10L^^12 + 10;

void main() {
  long[] ns = [0, 0];
  for (long k = 2; ; ++k) {
    long l = 0, r = 0;
    long n = k;
    foreach (i; 1 .. k) {
      if (i & 1) {
        const len = (n - r) + (n - i);
        r = i;
        n += (len - 1);
      } else {
        const len = (n - i) + (n - l);
        l = i;
        n += (len - 1);
      }
    }
    ns ~= n;
    if (n >= MAX_N) {
      break;
    }
  }
  debug {
    writeln("|ns| = ", ns.length);
    writeln(ns);
    stdout.flush;
  }
  
  try {
    for (; ; ) {
      const N = readLong;
      
      const k = ns.lowerBound(N);
      const ans = N - k;
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}