program z6_19;
uses crt;
const n=10;
var x,s,i,max:integer;
function firstnum(q:integer):integer;
var s:string;c,m:integer;
begin
str(q,s);
val(s[1],m,c);
firstnum:=m;
end;
begin
max:=-1;
for i:=1 to n do begin
resdln(x);
if s>max then begin
max:=s;
end;
end;
writeln(max:7);
readln;