Uses
CRT;
Var
sum,sr:real;
i,a,kol,ind:integer;
begin
ClrScr;
write('- 0');
writeln;
kol:=0;
sum:=0;
i:=1;
ind:=0;
repeat
begin
write(' ',kol+1,':=');
readln(a);
inc(kol);
if a=0 then
begin
ind:=i;
end;
if a<>0 then
sum:=sum+a;
inc(i);
end;
until a=0;
if ind=1 then
writeln('---')
else
begin
sr:=sum/(kol-1);
writeln('Sr:=',sr);
end;
readln;
end.