Zzuli:1058 solving inequalities

Title Description

Known inequality 1！+2！+3！+...+m！‹n, Please program the user specified n The value is calculated and the result satisfying the inequality is output m The integer solution of .

Input

Enter an integer n,n by int Positive integer in range .

Output

Output m Value range of , See the output sample for the specific format .

The sample input  Copy

2000000000

Sample output  Copy

m<=12

Tips

Note the type overflow problem in the calculation process

#include <stdio.h>
int main()
{
	int n,i,mul=1;
	scanf("%d",&n);
	double sum=0;
	for(i=1;;i++)
	{
		mul=i*mul;
		sum=sum+mul;
	if(sum>=n)
	{
	printf("m<=%d",i-1);
	break;}
	}
	return 0;
}