I am trying to put the id from database.saveresult return values and then the matching value from the citylist list into this map below, but I get an error "Method does not exist or incorrect signature: void put(sumchans__City_Master__c, Id) from the type Map<String,String>"
 

Database.SaveResult[] saveCityMaster = Database.Insert(cityList, false);
        Map<String,String> findCityId = new Map<String,String>();
        for (Database.SaveResult sr : saveCityMaster) {
            if (!sr.isSuccess()) {
                findCityId.put(cityList.get(0),sr.getId());
            }
        }