Q6. Find the dc input bias cancelling resistor

Consider the analogue integrator below with explicitly shown V_{OS}=2\text{mV} input dc offset voltage at the non-inverting input; and  input bias currents I_B=0.1\mu\text{A} and input offset current  I_{OS}=20\text{nA} (which can be used to calculate I_{BI} and I_{BN} below). To provide a finite dc gain, a resistor R_2=1\text{M}\Omega is connected across the capacitor C_2=10\text{nF}. To compensate for the effect of I_B, a resistor R_3 is connected to the non-inverting input terminal. Find the value of R_3. Here, R_1=10\text{k}\Omega.