1 #define LOCAL
  2 #include<cstring>
  3 #include<cstdio>
  4 #include<cstdlib>
  5 #include<algorithm>
  6 #include<iostream>
  7 using namespace std;
  8 const int maxn=1000100;
  9 
 10 struct node
 11 {
 12     int lef,rig; //通过和的大小来比较种类是否一样
 13     int cnt; //跟新的种类
 14     int type; //保存的种类
 15     int mid(){
 16       return lef+(rig-lef>>1);
 17     }
 18 };
 19 
 20 node sac[maxn<<3];
 21 int ans[maxn*4],ct;
 22 
 23 void Build(int left,int right,int pos)
 24 {
 25   sac[pos]=(node){left,right,0,2};   //单一
 26   if(left==right) return ;
 27   int mid=sac[pos].mid();
 28   Build(left,mid,pos<<1);
 29   Build(mid+1,right,pos<<1|1);
 30 }
 31 
 32 void Update(int left,int right,int pos,int val)
 33 {
 34    if(left<=sac[pos].lef&&sac[pos].rig<=right)
 35     {
 36       sac[pos].cnt=val;
 37       sac[pos].type=val;
 38       return ;
 39     }
 40 
 41     if(sac[pos].cnt!=0)
 42     { //向下更新一次
 43       sac[pos<<1|1].cnt=sac[pos<<1].cnt=sac[pos].cnt;
 44       sac[pos<<1|1].type=sac[pos<<1].type=sac[pos].type;
 45       sac[pos].cnt=0;
 46     }
 47     int mid=sac[pos].mid();
 48     if(mid>=left)
 49        Update(left,right,pos<<1,val);
 50     if(mid<right)
 51        Update(left,right,pos<<1|1,val);
 52       if(sac[pos<<1].type==sac[pos<<1|1].type)
 53           sac[pos].type=sac[pos<<1].type;
 54         else sac[pos].type=0;
 55 }
 56 
 57 void Query(int pos,int left,int right) {//查找操作
 58 
 59    if(sac[pos].lef>right||sac[pos].rig<left)
 60         return ;
 61 
 62     if(sac[pos].type)
 63     {
 64       ans[ct++]=sac[pos].type;
 65       return ;
 66     }
 67    Query(pos<<1,left,right);
 68    Query(pos<<1|1,left,right);
 69 
 70 }
 71 
 72 int main()
 73 {
 74   int n,m,a,b,c;
 75   char s[2];
 76   #ifdef LOCAL
 77      freopen("test.in","r",stdin);
 78   #endif
 79   while(scanf("%d%d",&n,&m),n+m!=0){
 80      Build(1,n,1);
 81      ct=0;
 82      while(m--)
 83      {
 84        scanf("%s",s);
 85        if(s[0]==‘P‘){
 86          scanf("%d%d%d",&a,&b,&c);
 87          Update(a,b,1,c);
 88        }
 89        else
 90        {
 91              scanf("%d%d",&a,&b);
 92           Query(1,a,b);
 93           sort(ans,ans+ct);
 94           printf("%d",ans[0]);
 95          for(int i=1;i<ct;i++){
 96             if(ans[i]!=ans[i-1])
 97               printf(" %d",ans[i]);
 98          }
 99           printf("\n");
100           ct=0;
101        }
102      }
103   }
104   return 0;
105 }