uses
crt;
var
a: array [1 .. 100] of integer;
n, i, k: integer;
begin
read(n);
k := 0;
for i := 1 to n do
begin
read(a[i]);
end;
for i := 1 to n do
begin
if (a[i] <= sqr(i)) then
k := k + a[i];
end;
write(k);
readln;
readln;
end.