var
a:longint;
min:integer;
begin
readln(a);
min:=9;
repeat
if a mod 10<min then min:=a mod 10;
a:=a div 10;
until a=0;
writeln(min);
readln;
end.
var
a:longint;
min:integer;
begin
readln(a);
min:=9;
repeat
if a mod 10<min then min:=a mod 10;
a:=a div 10;
until a=0;
writeln(min);
readln;
end.