SEAMO X 2019 — Paper C — Grade 5–6 Question 12

Given $1-\dfrac1{r+\dfrac1{s+\dfrac1{t+\dfrac1{u+1/s}}}}=\dfrac1{1+\dfrac1{2+\dfrac1{2+\dfrac1{3+1/3}}}}$, find $r+s+t+u$.