uses crt;
var a,b,c: integer;
procedure nhap;
var a,b,c:integer;
begin
write ('nhap canh thu nhat: '); readln (A);
write ('nhap canh thu hai: '); readln (B);
write ('nhap canh thu ba: '); readln (c);
end;
function cv(a,b,c: integer): longint;
begin
cv:=a+b+c;
end;
begin
clrscr;
nhap;
writeln ('chu vi la: ',cv(a,b,c));
readln;
end.