import std.stdio,
       std.conv,
       std.string,
       std.range,
       std.math,
       std.algorithm,
       std.bigint;

void main()
{
    auto K = readln.strip.to!int;

    "%.18s".writefln(
        [2,3,5,7,11,13].map!(P => [4,6,8,9,10,12].count!(C => P*C==K)).sum.to!real/36
    );
}