#include <stdio.h>

/// <summary>
/// 入力された数字を返す
/// </summary>
/// <returns></returns>
int ReadNum() {
	int negate = 0;
	char c = getchar();
	int num = 0;
	int numCnt = 0;
	while (c != '\n') {
		if (c == '-') {
			negate = 1;
		}
		else {
			num = num * 10 + c - '0';
		}

		c = getchar();
	}
	if (negate == 1) {
		num *= -1;
	}
	return num;
}

void bisk() {
	int n = ReadNum();
	if (n == 1) {
		printf("0\n");
		return;
	}
	int bis = 1;
	int cnt = 0;
	while (1) {
		bis *= 2;
		cnt++;
		if (bis >= n) break;
	}
	printf("%d\n", cnt);
}

int main()
{
	bisk();
}