type pc=array[1..3] of longint;
var h:array[1..40000] of pc;
a,t,c:pc;
i,n,k,z:longint;
res,m:int64;
procedure swap(var a,b:pc);
var y:pc;
begin
  y:=a;
  a:=b;
  b:=y;
end;
procedure sd;
var i,x:longint;
begin
  i:=1;
  x:=1;
  while 2*x<=k do
  begin
    if h[2*x][1]<h[i][1] then i:=2*x;
    if (2*x+1<=k) and (h[2*x+1][1]<h[i][1]) then i:=2*x+1;
    if x=i then break;
    swap(h[i],h[x]);
    x:=i;
  end;
end;
procedure remove;
begin
  h[1]:=h[k];
  Dec(k);
  sd;
end;
procedure add(a:pc);
var c:longint;
begin
  Inc(k);
  h[k]:=a;
  c:=k;
  while (c>1) and (h[c div 2][1]>h[c][1]) do
  begin swap(h[c],h[c div 2]); c:=c div 2; end;
end;
begin
assign(input,'horizon.in'); reset(input);
assign(output,'horizon.out'); rewrite(output);
readln(n);
k:=0;
res:=0;
for i:=1 to n do
begin
  for z:=1 to 3 do read(a[z]);
  add(a);
end;
a:=h[1];
remove;
while k>0 do
begin
  t:=h[1];
  if (t[1]>=a[2]) then
  begin
    m:=a[2]-a[1];
    res:=res+m*a[3];
    a:=t;
    remove;
    continue;
  end;
  if a[3]<=t[3] then
  begin
    m:=t[1]-a[1];
    res:=res+m*a[3];
    if a[2]>t[2] then
    begin
      c[1]:=t[2];
      c[2]:=a[2];
      c[3]:=a[3];
      add(c);
    end;
    a:=t;
    remove;
  end
  else begin
    if a[2]<t[2] then
    begin
      t[1]:=a[2];
      h[1]:=t;
      sd;
    end
    else remove;
  end;
end;
m:=a[2]-a[1];
res:=res+m*a[3];
writeln(res);
close(input); close(output);
end.