% NOIP2013-J T4
%input

int: n;
int: m;
array[1..m] of int:s;
array[1..m] of set of int:pset;

%description

array[1..n] of var 1..n:level;
array[1..m] of var 1..n:split;
array[1..m] of var 1..n:start;
array[1..m] of var 1..n:end;
var set of 1..n: level_set;

set of int:all_station=1..n;

constraint forall(i in 1..m)(
  forall(station in pset[i])(
    start[i]<=station /\ end[i]>=station
  )
);

constraint forall(i in 1..m)(
  forall(station in pset[i])(
    level[station]>=split[i]
  )
);
constraint forall(i in 1..m)(
forall(station in (all_station diff pset[i]))(
    if(station>=start[i] /\ station<=end[i])
    then level[station]<split[i] endif
  )
);
%如果这趟车次停靠了火车站 x，则始发站、终点站之间所有级别大于等于火车站 x 的都必须停靠

constraint forall(l in level)(l in level_set);

%solve

solve minimize (card(level_set));

%output

output [show(card(level_set))];