How to solve a cryptarithm? Given multiplication is
$$\begin{array}{cccccc}
  &amp;   &amp;   &amp; P &amp; E &amp; N \\
  &amp;   &amp;   &amp; I &amp; N &amp; K \\\hline
  &amp;   &amp; L &amp; K &amp; P &amp; R \\
  &amp; I &amp; R &amp; T &amp; N &amp;   \\
E &amp; A &amp; K &amp; N &amp;   &amp;   \\\hline
L &amp; E &amp; T &amp; T &amp; E &amp; R
\end{array}$$

how to find the values of the letters?
Start from N*N ends in N, so N must be 5 or 6 (can't be 0 or 1 from the second line in the sum).  Then I*N ends in N (and I !=1) says N is 5 and I is odd.  Then K is even and R is 0.  Continue
6 1 5 * 354

 2 4 6 0


3 0 7 5

 1 8 4 5

2 1 7 7 1 0