Flash Bulb battery depletion
$$1000\mathrm{\ mA \cdot h}\times110\mathrm{\ V} = 396\mathrm{\ kJ}$$

$$100\frac{\mathrm{\ W \cdot s}}{\text{flash}} = 100\frac{\mathrm{\ J}}{\text{flash}}$$

$$\frac{396\mathrm{\ kJ}}{100\frac{\mathrm{\ J}}{\text{flash}}} = 3960\text{ flashes}$$