boj17626.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class boj17626 {

    static int[] dp;
    static int min;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());

        dp = new int[n + 1];
        dp[0] = 0;
        dp[1] = 1;

        solve(n);
        System.out.println(dp[n]);
    }

    static void solve(int n) {
        for (int i = 2; i <= n; i++) {
            min = Integer.MAX_VALUE;
            for (int j = 1; j * j <= i; j++) {
                min = Math.min(min, dp[i - j * j]);
            }
            dp[i] = min + 1;
        }
    }
}