program waterfire;
const
fin='heaven.in';
fout='heaven.out';
month:array[1..12] of longint=(31,29,31,30,31,30,31,31,30,31,30,31);
 type
     tlist = array[1..366] of longint;

     var
n,s,s2,max,i,j:longint;
b: tlist;
data:array[0..366,0..366] of longint;
f,g:text;
procedure test(x,y:longint);
var
i,j:longint;
begin
for i:=1 to 12 do  begin
if x=i then begin
b[s]:=b[s]+y;
exit;
end;
if x<>i then
b[s]:=b[s]+month[i];
end;
end;
procedure qsort(var a : tlist);

    procedure sort(l,r: longint);
      var
         i,j,x,y: longint;
      begin
         i:=l;
         j:=r;
         x:=a[(l+r) div 2];
         repeat
           while a[i]<x do
            inc(i);
           while x<a[j] do
            dec(j);
           if not(i>j) then
             begin
                y:=a[i];
                a[i]:=a[j];
                a[j]:=y;
                inc(i);
                j:=j-1;
             end;
         until i>j;
         if l<j then
           sort(l,j);
         if i<r then
           sort(i,r);
      end;

    begin
       sort(1,max);
    end;

    procedure work;
    var
    i,j:longint;

    begin
     for i:=0 to n-1 do
      begin
      s:=b[i+1]-b[i]-1;
      if s>max then max:=s;
      end;
     max:=round(max/366*3600*24);
      end;


    begin
data[0,1]:=1;data[0,2]:=1;
assign(f,fin);reset(f);
assign(g,fout);rewrite(g);
readln(f,n);
for i:=1 to n do
begin
for j:=1 to 2 do
read(f,data[i,j]);
s:=i;
test(data[i,1],data[i,2]);
 end;
 qsort(b);
 work;
 write(g,max);
 close(g);
 close(f);
 end.