$${ } ^ { 137 } \mathrm { Cs } \text { is a typical long-lived waste product from fission reactors. Beginning }$$

$${ } ^ { 137 } \mathrm { Cs } \text { is a typical long-lived waste product from fission reactors. Beginning }$$ with the fission process: $$\mathrm { n } + { } ^ { 235 } \mathrm { U } \rightarrow { } ^ { 236 } \mathrm { U } \rightarrow { } ^ { 137 } \mathrm { I } + { } ^ { 95 } \mathrm { Y } + 4 \mathrm { n }$$
explain how ${ } ^ { 137 } \mathrm { Cs }$ is produced.