1 var
2 nnn,root,xx,nn,n,m,i,j:longint;ans:int64;
3 l,r,size,a,an,bn,am,bm:array[1..100000]of longint;
4 function new(x:longint):longint;
5 begin
6 inc(nn);
7 size[nn]:=1;a[nn]:=x; exit(nn);
8 end;
9
10 procedure insert(var t,x:longint);
11 begin
12 if t=0 then
13 begin
14 t:=new(x);
15 exit;
16 end;
17 inc(size[t]);
18 if x<a[t] then insert(l[t],x)
19 else insert(r[t],x);
20 end;
21 function search(t,x:longint):longint;
22 begin
23 search:=0;
24 while t<>0 do
25 begin
26 if (a[t]<=x)and(a[t]>search) then
27 search:=a[t];
28 if x<a[t] then
29 t:=l[t]
30 else t:=r[t];
31 end;
32 end;
33 function delete(var t:longint; x:longint):longint;
34 var rr,k:longint;
35 begin
36 dec(size[t]);
37 if (x=a[t])or((x<a[t])and(l[t]=0))or((x>a[t])and(r[t]=0)) then
38 begin
39 rr:=a[t];
40 if (l[t]=0)or(r[t]=0) then
41 t:=l[t]+r[t]
42 else a[t]:=delete(l[t],a[t]+1);
43 exit(rr);
44 end
45 else if a[t]>x then exit(delete(l[t],x))
46 else exit(delete(r[t],x));
47 end;
48 procedure sort1(l,r: longint);
49 var
50 i,j,xx,yy: longint;
51 begin
52 i:=l;
53 j:=r;
54 xx:=an[(l+r) div 2];
55 repeat
56 while an[i]<xx do
57 inc(i);
58 while xx<an[j] do
59 dec(j);
60 if not(i>j) then
61 begin
62 yy:=an[i];
63 an[i]:=an[j];
64 an[j]:=yy;
65 yy:=bn[i];
66 bn[i]:=bn[j];
67 bn[j]:=yy;
68 inc(i);
69 j:=j-1;
70 end;
71 until i>j;
72 if l<j then
73 sort1(l,j);
74 if i<r then
75 sort1(i,r);
76 end;
77 procedure sort2(l,r: longint);
78 var
79 i,j,xx,yy: longint;
80 begin
81 i:=l;
82 j:=r;
83 xx:=am[(l+r) div 2];
84 repeat
85 while am[i]<xx do
86 inc(i);
87 while xx<am[j] do
88 dec(j);
89 if not(i>j) then
90 begin
91 yy:=am[i];
92 am[i]:=am[j];
93 am[j]:=yy;
94 yy:=bm[i];
95 bm[i]:=bm[j];
96 bm[j]:=yy;
97 inc(i);
98 j:=j-1;
99 end;
100 until i>j;
101 if l<j then
102 sort2(l,j);
103 if i<r then
104 sort2(i,r);
105 end;
106
107 begin
108 readln(n,m);
109 for i:=1 to n do
110 readln(an[i],bn[i]);
111 for i:=1 to m do
112 readln(am[i],bm[i]);
113 sort1(1,n);sort2(1,m);
114 j:=1;
115 for i:=1 to m do
116 begin
117 if nnn>n then break;
118 while (an[j]<=am[i])and(j<=n) do
119 begin
120 insert(root,bn[j]);
121 inc(j);
122 end;
123 xx:=search(root,bm[i]);
124 if xx<>0 then
125 begin
126 inc(nnn);
127 ans:=ans+am[i];
128 delete(root,xx);
129 end;
130 end;
131 writeln(ans);
132 end.
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