type
zn=array [-1..60000] of integer;
var
a:zn; i,j,n:integer;
begin
readln(n);
a[-1]:=0; a[0]:=0;
a[1]:=1;
for i:=2 to n do a[i]:=a[i-1]+a[i-2];
writeln(a[n]);
end.
错了 少打了一个
type
zn=array [-1..60000] of integer;
var
a:zn; i,j,n:integer;
begin
readln(n);
a[-1]:=0; a[0]:=0;
a[1]:=1; a
for i:=2 to n do a[i]:=a[i-1]+a[i-2]+a[i-3];
writeln(a[n]);
end.