题目链接：http://codeforces.com/contest/460/problem/A
#include <iostream>
using namespace std;
int main()
{
int m,n;
cin>>m>>n;
int sum;
for(sum=1; m>0; sum++)
{
m--;
if(sum % n == 0)
m++;
}
sum--;
cout<<sum<<endl;
return 0;
}
