题解

#include <bits/stdc++.h>
using namespace std;
int main(){
int n,m,sum=0,day=0;
cin>>n>>m;
int i=m;
while(sum<=n){
sum+=i;
day++;
i++;
if(sum>n){
day--;
break;
}else if(sum==n){
break;
}
}
cout<<day;
return 0;
}