Víš aspoň k jakému google účtu je telefon přiřazený? Dokážeš se na ten účet přihlásit?
Pak by byla možnost resetovat to heslo přes google účet:

Unlock with Google Account
You can also unlock your Lenovo S5 Android device with Google account if your phone has Forgot password option. Your mobile must have an active internet connection to reset with this option.

Follow these steps to Unlock your Android mobile with google account.

First, Power On your Lenovo S5 mobile.
After the number of unsuccessful attempts on your mobile, You will see the Forgot pattern option.
Now Tap on the Forgot pattern option.
Next, Enter your Google Account username and password.
Afterward, Tap on the Sign In.
Then Choose a new password and unlock your device.
Finally, Your phone will be unlocked.