优化,尽可能榨干这段代码,谢谢

#include<iostream>
#include<cstdio>
using namespace std;
int main(){
    int a,b = 1;
    double sum = 1;
    cin>>a;
    while (sum <= a){
    	b += 1;
    	sum += 1.0/b;
	}
	printf("%d",b);
	return 0;
}