Your objective for this question is to develop a program which will generate a fibonacci number. The fibonacci function is defined as such: - $f(0) = 0$ - $f(1) = 1$ - $f(n) = f(n-1) + f(n-2)$ Your program should be able to handle values of $n$ in the range $0$ to $50$.

**Multiple test cases, please process until $n=-1$.** Each test case consists of one integer $n\ (0\le n\le 50)$ in a single line.

Print out the answer in a single line for each test case.

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