SuperLong Sums
Program P1048;
  Var
    N,Temp,Plus,Temp1:Longint;
    N1,N2,S1,S2:Byte;
  Begin
    Readln(N);
    Readln(N1,N2);
    S1:=N1+N2;
    If N=1 Then
      Begin
        Write(S1);
        Halt;
      End;
    For Temp:=1 To N-1 Do
      Begin
        Readln(N1,N2);
        S2:=N1+N2;
        If S2=9 Then Inc(Plus)
          Else
            If S2>9 Then
              Begin
                If Plus<>0 Then
                  Begin
                    Write(S1+1);
                    For Temp1:=1 To Plus Do Write('0');
                    Plus:=0;
                    Dec(S2,10);
                  End
                  Else
                    Begin
                      Dec(S2,10);
                      Write(S1+1);
                    End;
              End
              Else
                Begin
                  Write(S1);
                  If Plus<>0 Then
                    Begin
                      For Temp1:=1 To Plus Do Write('9');
                      Plus:=0;
                    End;
                End;
        If Plus=0 Then S1:=S2;
      End;
    If Plus<>0 Then
      Begin
        Write(S1);
        For Temp:=1 To Plus Do Write('9');
      End
      Else Write(S2);
    Writeln;
  End.