---

import math
import sys

SERIES = (0.5, 0.75, 1.0, 1.5, 2.5, 4.0, 6.0, 10.0)


def parse_length(s):
    if s is None:
        return None
    p = s[1:] if s.startswith('+') else s
    if not p or not p.isascii() or not p.isdigit() or len(p) > 4:
        return None
    v = int(p)
    return v if 1 <= v <= 100 else None


def parse_section(s):
    if s is None:
        return None
    try:
        v = float(s.replace(',', '.'))
    except ValueError:
        return None
    if not math.isfinite(v):
        return None
    for x in SERIES:
        if abs(v - x) < 1e-9:
            return x
    return None


def main():
    line = sys.stdin.readline()
    tok = line.split()

    length = parse_length(tok[0] if len(tok) > 0 else None)
    section = parse_section(tok[1] if len(tok) > 1 else None)
    if len(tok) > 2:
        section = None

    if length is None and section is None:
        print(999)
        return
    if length is None:
        print(777)
        return
    if section is None:
        print(888)
        return

    U, rho, cosphi = 220.0, 0.0175, 0.95
    dU = 0.10 * U
    R = rho * 2 * length / section  # два провода: туда и обратно
    I = dU / (R * cosphi)
    res = math.floor(I + 1e-9)
    print(max(1, min(64, res)))


main()