What mass of this substance must evaporate in order to freeze 180 {rm g} of water initially at 17^circ {rm C}?

What mass of this substance must evaporate in order to freeze 180 {rm g} of water initially at 17^circ {rm C}? (The heat of fusion of water is 334 {rm J/g}; the specific heat of water is 4.18 {rm J/g cdot K}.)