3. Color each vertex of a square pyramid with one color, and make the endpoints of the same edge have different colors. If only 5 colors are available, the number of different coloring methods is $\qquad$ .
(Given that there are 5 colors, 1, 2, 3, 4, 5, to color the pyramid $S-ABCD$. Since $S$, $A$, and $B$ are colored differently, there are $5 \times 4 \times 3=60$ coloring methods. Assuming $S$, $A$, and $B$ are already colored, we then categorize and discuss the coloring of $C$ and $D$, which have 7 coloring methods. Therefore, there are a total of $60 \times 7=420$ coloring methods.)