var m, n, r, q;procedure gcd;begin    repeat        q := m / n;        r := m - q * n;        m := n;        n := r;    until r = 0end;begin    read(m);    read(n);    if m < n then        begin            r := m;            m := n;            n := r;        end;    begin        call gcd;        write(m);    end;end.