import std;

void main () {
    int p = 10 ^^ 9;
    while (true) {
        writeln(p);
        stdout.flush;
        int r = readln.chomp.to!int;
        if (r == 1) break;

        p /= 2;
    }
}

void read (T...) (string S, ref T args) {
    import std.conv : to;
    import std.array : split;
    auto buf = S.split;
    foreach (i, ref arg; args) {
        arg = buf[i].to!(typeof(arg));
    }
}