Maximum Mass Without Wire Breaking

Wires W1 and W2 are made of same material having the breaking stress of 1.25×109N∕m2. W1 and W2 have cross-sectional area of 8×10−7m2 and 4×10−7m2, respectively. Masses of 20‌kg and 10‌kg hang from them as shown in the figure. The maximum mass that can be placed in the pan without breaking the wires is .......... kg.
(Use, g=10m∕s2)