Problem 344

Secret Code. Two conspirators had a secret code. Sometimes their correspondence contained simple arithmetic operations that looked completely innocent. However, in the code, each of the ten digits represented its own letter of the alphabet. Once, a sum was encountered which, after substituting the corresponding letters for the digits, took the form

$$\begin{gathered} F L Y \\ F O R \\ Y O U R \\ \hline L I F E^{* *} \end{gathered}$$

It would be interesting to restore this sum, knowing that $I$ and $O$ represent the digits 1 and 0, respectively.