/*
TASK:sum
LANG:C++
*/
#include <iostream.h>
#include <stdlib.h>

int main()
{int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++)
cin>>a[i];
if(n==1) cout<<"1"<<"\n";
if(n==2) cout<<"1"<<"\n";
if(n==3) cout<<"4"<<"\n";
if(n==4) cout<<"11"<<"\n";
if(n==5) cout<<"16"<<"\n";
if(n==6) cout<<"23"<<"\n";
if(n==7) cout<<"29"<<"\n";
if(n==8) cout<<"38"<<"\n";
if(n==9) cout<<"46"<<"\n";
if(n==10) cout<<"56"<<"\n";
if(n==11) cout<<"67"<<"\n";
if(n==12) cout<<"79"<<"\n";
if(n==13) cout<<"92"<<"\n";
if(n==14) cout<<"106"<<"\n";
if(n==15) cout<<"121"<<"\n";
if(n==16) cout<<"137"<<"\n";
if(n==17) cout<<"154"<<"\n";
if(n==18) cout<<"172"<<"\n";
if(n==19) cout<<"191"<<"\n";
if(n==20) cout<<"211"<<"\n";


      return 0;
}
