Transfiguration (English
Transfiguration; literally «transfiguration», «transfiguration») — a discipline that studies the magical ways transformation of some objects into others, inanimate objects into living ones and vice versa, as well as one living objects into others. A special case of transfiguration is the creation of objects from nothing or their disappearance. The subject is extremely complex and requires certain magical powers and strict concentration. Transfiguration requires a magic wand and knowledge of the appropriate formula.
Known Number
\(n >= 2\) transfigure to sum
\(1 \cdot 2+2 \cdot 3+...+(n-1) \cdot n\).
Print your answer as a calculated expression and its value exactly as shown in the example.
Input
Enter a natural number.
Imprint
Print the answer to the problem.
Examples
| # |
Input |
Output |
| 1 |
4 |
1*2+2*3+3*4=20 |
| 2 |
2 |
1*2=2 |
Запрещенные операторы:list;[