uses crt;
var i,m,n:integer;
p,s:longint;
begin
clrscr;
write('M N -> ');
readln(m,n);
p:=1;
for i:=1 to m do p:=p*i;
s:=p;
for i:=m+1 to n do
begin
p:=p*i;
s:=s+p;
end;
writeln('S=',s);
readln;
end.
uses crt;
var i,m,n:integer;
p,s:longint;
begin
clrscr;
write('M N -> ');
readln(m,n);
p:=1;
for i:=1 to m do p:=p*i;
s:=p;
for i:=m+1 to n do
begin
p:=p*i;
s:=s+p;
end;
writeln('S=',s);
readln;
end.