little bit of Mathematics

take two numbers x and y.
add them.
we get z = x + y
so we have: x, y, x+y
then repeat the process and get:
x, y, x+y, y + x+y, x+y + (y+x+y), y+x+y + (x+y + y+x+y)..........
find ten numbers like that.
now you can find the sum of these numbers very easily.
just get the seventh number in the list.
multiply it by 11, and get the answer.
Example:
1. 12

2. 13

3. 25

4. 38

5. 63

6. 101

7. 164

8. 265

9. 429

10.694
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sum = 1804
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and 164 * 11 = 1804

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