#include <iostream>
#include <math.h>
using namespace std;
bool judge(float n, float i, float dpI){
if(i-n==0) {
float temp = (dpI-1)/n;
if(temp-(int)temp == 0)
return true;
else
return false;
} else
return judge(n, i+1, dpI -1 - (dpI-1)/n);
}
int main()
{
double n;
cin>>n;
double i=1.0f;
while(true){
if(judge(n, 1, i)){
cout<<i<<endl;
break;
} else{
i++;
}
}
return 0;
}