Verified answer

Program n1;

function st(x,n: longint): longint;

begin

if n=0 then st:=1

else if n=1 then st:=x

else if n mod 2=0 then st:=st(x*x,n div 2)

else st:=st(x*x,n div 2)*x;

end;

var n,s,i: longint;

begin

readln(n);

s:=0;

for i:=st(10,n-1) to st(10,n)-1 do s:=s+i;

writeln(s);

end.