import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;

public class Euler985 {
    public static void main(String[] args) {
        System.out.println(new Euler985().run());
    }

    public String run() {
        MathContext mc = new MathContext(100, RoundingMode.HALF_UP);

        // K = pi / (3 * 2^19)
        BigDecimal pi = new BigDecimal(
                "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679");
        BigDecimal divisor = new BigDecimal(3).multiply(new BigDecimal(2).pow(19), mc);
        BigDecimal K = pi.divide(divisor, mc);

        BigDecimal K2 = K.multiply(K, mc);
        BigDecimal K3 = K2.multiply(K, mc);
        BigDecimal K4 = K3.multiply(K, mc);
        BigDecimal K5 = K4.multiply(K, mc);

        // sinK = K - K^3/6 + K^5/120
        BigDecimal sinK = K.subtract(K3.divide(new BigDecimal(6), mc), mc).add(K5.divide(new BigDecimal(120), mc), mc);

        // cosK = 1 - K^2/2 + K^4/24
        BigDecimal cosK = BigDecimal.ONE.subtract(K2.divide(new BigDecimal(2), mc), mc)
                .add(K4.divide(new BigDecimal(24), mc), mc);

        // sqrt(3)
        BigDecimal sqrt3 = new BigDecimal(3).sqrt(mc);

        // cos_pi3_plus_K = 0.5 * cosK - (sqrt3 / 2) * sinK
        BigDecimal half = new BigDecimal("0.5");
        BigDecimal cos_pi3_plus_K = half.multiply(cosK, mc)
                .subtract(sqrt3.divide(new BigDecimal(2), mc).multiply(sinK, mc), mc);

        // V = 0.5 - cos_pi3_plus_K
        BigDecimal V = half.subtract(cos_pi3_plus_K, mc);

        // a_exact = (1 + sqrt(1 + 2V)) / 2V
        BigDecimal twoV = new BigDecimal(2).multiply(V, mc);
        BigDecimal onePlus2V = BigDecimal.ONE.add(twoV, mc);
        BigDecimal sqrtOnePlus2V = onePlus2V.sqrt(mc);
        BigDecimal a_exact = BigDecimal.ONE.add(sqrtOnePlus2V, mc).divide(twoV, mc);

        long a = a_exact.setScale(0, RoundingMode.FLOOR).longValue() + 1;

        return String.valueOf(3 * a + 1);
    }
}