var s1,s,s2,s3:string; i,j:integer; begin readln(s1); readln(s2); readln(s3); s:=s1+s2; for i:=1 to length(s) do for j:=i+1 to length(s) do if s[i]>s[j] then swap(s[i],s[j]);

for i:=1 to length(s3) do for j:=i+1 to length(s3) do if s3[i]>s3[j] then swap(s3[i],s3[j]); if s3=s then PRINT('YES') else PRINT('NO'); end.