Coding-Decoding - RUSTICATE

The transformation for each letter of RUSTICATE to QTTUIDBSD is: R (-1) $\rightarrow$ Q, U (-1) $\rightarrow$ T, S (+1) $\rightarrow$ T, T (+1) $\rightarrow$ U, I (+0) $\rightarrow$ I, C (+1) $\rightarrow$ D, A (+1) $\rightarrow$ B, T (-1) $\rightarrow$ S, E (-1) $\rightarrow$ D.

Applying same pattern to STATISTIC: S (-1) $\rightarrow$ R, T (-1) $\rightarrow$ S, A (+1) $\rightarrow$ B, T (+1) $\rightarrow$ U, I (+0) $\rightarrow$ I, S (+1) $\rightarrow$ T, T (+1) $\rightarrow$ U, I (-1) $\rightarrow$ H, C (-1) $\rightarrow$ B.

Code = RSBUITUHB.