program p1020;const e='error';var i,j,n,po:longint; s,k:string; ok:boolean;begin readln(n); for j:=1 to n do begin readln(s); readln(k); po:=0;ok:=false; if k[1]='D' then begin po:=pos(k[3],s); if po<>0 then begin delete(s,po,1); writeln(s); end else writeln(e); end; if k[1]='I' then begin for i:=length(s) downto 1 do if s[i]=k[3] then begin po:=i; break; end; if po<>0 then begin insert(k[5],s,po); writeln(s); end else writeln(e); end; if k[1]='R' then begin for i:=1 to length(s) do if s[i]=k[3] then s[i]:=k[5]; writeln(s) end; end;end.