program transz;
const
  maxtin=10000000;
var
  i,j,l,n,m,k,e,q,p,a,b,c,min,minn,cost:longint;
  change:boolean;
  map,w:array[1..100,1..100]of longint;
  pre,last:array[0..100]of longint;
  flag:array[1..100]of boolean;
  no:array[1..100000,1..3]of longint;
  d:array[1..100]of longint;
procedure init;
begin
  assign(input,'transz.in');
  reset(input);
  assign(output,'transz.out');
  rewrite(output);
  read(n,m,k,e);
  for i:=1 to m do
    for j:=1 to m do
      if i<>j then
        map[i,j]:=maxtin;
  for i:=1 to e do
  begin
    read(a,b,c);
    map[a,b]:=c;
    map[b,a]:=c
  end;
  read(q);
  for i:=1 to q do
  begin
    read(c,a,b);
    no[i,1]:=c;
    no[i,2]:=a;
    no[i,3]:=b
  end;
  fillchar(last,sizeof(last),true)
end;

procedure yuchuli;
var
  l1,l2:longint;
begin
  fillchar(flag,sizeof(flag),true);
  for j:=1 to q do
    if (l>=no[j,2]) and (l<=no[j,3]) then
      flag[no[j,1]]:=false;
  for l1:=1 to m do
    for l2:=1 to m do
      if (flag[l1]=false) or (flag[l2]=false) then
        w[l1,l2]:=maxtin
      else w[l1,l2]:=map[l1,l2];
  fillchar(flag,sizeof(flag),true);
  change:=false;
  for j:=1 to m do
    d[j]:=w[1,j]
end;

procedure dijkstra;
begin
  for i:=1 to m-1 do
  begin
    min:=maxtin;
    for j:=1 to m do
      if (min>d[j]) and flag[j] then
      begin
        min:=d[j];
        minn:=j
      end;
    flag[minn]:=false;
    for j:=1 to m do
      if d[j]>d[minn]+w[minn,j] then
      begin
        d[j]:=d[minn]+w[minn,j];
        pre[j]:=minn
      end
  end
end;

procedure panduan;
var
  x,y:longint;
begin
  x:=pre[m];
  y:=last[m];
  repeat
   if x<>y then
   begin
     change:=true;
     break
   end;
   x:=pre[x];
   y:=last[y]
  until x=0;
  for j:=1 to m do
    last[j]:=pre[j]
end;

procedure jisuan;
begin
  cost:=cost+d[m];
  if change then cost:=cost+k
end;

procedure main;
begin
  for l:=1 to n do
  begin
    yuchuli;
    dijkstra;
    panduan;
    jisuan
  end
end;

procedure print;
begin
  writeln(cost-k);
  close(input);
  close(output)
end;

begin
  init;
  main;
  print
end.