Gálnierin $\Gamma$.

Each face of a rectangular parallelepiped $3 \times 4 \times 5$ is divided into unit squares. Is it possible to inscribe a number in each square such that the sum of the numbers in each checkerboard ring of width 1, encircling the parallelepiped, equals 120?
For example, fill in 9 in all the squares of the faces $4 \times 5$, 8 in all the squares of the faces $3 \times 5$, and 5 in all the squares of the faces $3 \times 4$:

$2(4 \cdot 9+3 \cdot 8)=2(5 \cdot 9+3 \cdot 5)=2(5 \cdot 9+4 \cdot 5)=120$.

## Answer

It is possible.