import std.experimental.all;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

void main() {
    long n = read!long;

    int ans = 0;
    long x = 1;
    while (x < n) {
        x *= 2;
        ans++;
    }
    writeln(ans);
}