program TBC;
uses crt;
var a: integer;
s: real;
begin
clrscr;
writeln('nhap so a: '); readln(a);
s:= s+a;
writeln('nhap so b: '); readln(a);
s:= s+a;
writeln('nhap so c: '); readln(a);
s:= s+a;
writeln('nhap so d: '); readln(a);
s:= s+a;
s:= s/4;
writeln('TBC la: ',s:2:1);
readln
end.