A power system consists of 400 buses out of which 'G' buses are connected with generators, 20 buses are the ones with controlled reactive power support and 10 buses are the ones with fixed shunt capacitors. All other buses are load buses. It is proposed to perform a load flow analysis using the Newton-Rapson method. The size of the Newton-Rapson Jacobian matrix is 750 × 750. Then the number of generator buses are equals to