Multiple Inputs to Script Component

I have SSIS flow performing the following

Step1: Extract Records from Source Table ODBC source

Step 2: Derived field for transformation-> error output of step 2 is connected to step 2a

  Step 2a. Script Component for Transformation -- to capture Error Column /Error Description and other error related fields.

My question is , how do I connect error output of step1 as well to this script. When I try to connect it says "All available inputs on target component are connected to outputs"

Following is the code in my script

 public override void Input0_ProcessInputRow(Input0Buffer Row)
    {
        /*
         * Add your code here
         */

        Row.ErrorDescription = this.ComponentMetaData.GetErrorDescription(Row.ErrorCode);
        Row.TableName = "TXXXXXX";
        Row.Key = Row.CLIENT.ToString() +"|"+ Row.LSTUPDTIMESTAMP.ToString();
        var componentMetaData130 = this.ComponentMetaData as IDTSComponentMetaData130;
        if (componentMetaData130 != null)
        {
            Row.ColumnName = componentMetaData130.GetIdentificationStringByID(Row.ErrorColumn);
        }
    }

}