$\triangle$ Let's pay attention to the last two columns. Since the addition of the same digits C and C results in different digits, the sum in the fifth column must be at least 10, which means C is not less than 5.

Let's look at the third column: when can the sum $\mathrm{O}+\mathrm{O}$ end with the same digit O? This is only possible when O is zero or nine. But O cannot be zero, since 1 is carried over from the fourth column to the third; therefore, O is nine.

Let's return to the digit C. Taking the previous into account, the inequality $5 \leq \mathrm{C} \leq 8$ holds. Let's consider all four possible values of C (do this yourself).

Answer: $35977+35977=71954$.
## KPOCC

$+$

KPOCC

SPORT,

where each letter represents a digit, and the same letters represent the same digits, different letters represent different digits. Find all solutions.

This is an example of a numerical riddle.