k一定是3？
```cpp
#include<bits/stdc++.h>
using namespace std;
int main()
{
long long n,k,sum=0;
cin>>n>>k;
while(n>=k)
{
n=n-k+1;
sum++;
}
cout<<n+sum*k;
return 0;
}
```
by cly312 @ 2023-10-02 18:22:29
@[cly312](/user/437243)
谢谢
by jiakunnan @ 2023-10-03 17:29:59