zzul1058_Java

import java.util.Scanner;

public class zzul1058 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        double fact = 1,sum = 0;
        for (int i = 1; ; i++) {
            fact *=i;//累乘
            sum +=fact;//累加
            if(sum >= n){
                System.out.printf("m<=%d",i-1);//第i次已经大于了，所以用它的前一个
                System.exit(-1);//终止代码
            }
        }

    }
}