vari,p,k,r,s:integer;mas: array[1..100] of integer;begins:=0;read(k);for i:=1 to k doread(mas[i]);
r:=mas[2]-mas[1];
for i:=1 to k dos:=s+mas[i];
writeln('raznost progressii=', r, ', summa elementov progressii=', s);end.