#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fastio ios::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
int main()
{
fastio;
int n;
cin >> n;
vector<int> dp(n + 1, n - 1);
dp[1] = 0;
for (int i = 1; i < n; i++)
{
dp[i + 1] = min(dp[i + 1], dp[i] + 1);
for (int j = 1;; j++) // 枚举蓄力时间
{
int x = i + j * j; // 蓄力跳跃的落点
if (x > n)
break;
dp[x] = min(dp[x], dp[i] + j + 1);
}
}
cout << dp[n];
