Diego earned employment income of $$112,000$ in $2023.$ The combined CPP and EI deduction for $2023$ totaled $$4,756.$ Of this amount, $$631$ was the CPP enhanced contribution. During $2023$ Diego enrolled in part$-$time studies at the local university paying tuition fees of $$1,500$ and donated $$2,000$ to a registered charity for tax purposes. What is the total of Diego's non$-$refundable tax credits for $2023?$