var
v,n,i,j,q:integer;
a:array[0..30] of integer;
begin
readln(n,v);
for i:=1 to v do
read(a[i]);
for i:=1 to v do
for j:=i to v do
if a[i]<a[j] then
begin
q:=a[i];
a[i]:=a[j];
a[j]:=q;
end;
i:=0;
repeat
i:=i+1;
if a[i]<=n then
n:=n-a[i];
until (n=0) or (i=v);
writeln(n);
end.