program test24moduler;
uses crt;
var
N,i,F: integer;
a: array [1..100000] of integer;
BEGIN
clrscr;
F:= 0;
readln(N);
for i:=1 to N do
begin
read(a[i]);
end;
for i:=1 to N do
begin
F:=F+(a[i]-1);
end;
writeln(F);
END.