program heaven;
const
fin='heaven.in';
fou='heaven.out';
a:array[1..12]of longint=(31,29,31,30,31,30,31,31,30,31,30,31);
var
b:array[1..400]of boolean;
all,max,q,i,j,n,x,y,m:longint;
total:real;
f1,f2:text;

procedure init;
begin
assign(f1,fin); assign(f2,fou);
reset(f1); rewrite(f2);
read(f1,n);
for i:=1 to n do
begin
 m:=0;
 read(f1,x,y);
 for j:=1 to (x-1) do
 m:=m+a[j];
 m:=m+y;
 b[m]:=true;
end;
end;

begin
init;
q:=0;
for i:=1 to 366 do
 if b[i]=true then
 begin
  all:=i-1-q;
  if all>max then max:=all;
  q:=i;
 end;
all:=366-q;
if all>max then max:=all;
total:=max*24*60*60/366;
max:=trunc(total);
total:=total-max;
if total>=0.5 then inc(max);
write(f2,max);
close(f1); close(f2);
end.