Fibonacci

int TheBigFibonacciLastDigit(int index) {
    return (int)(TheFibonaci(index)%10);
}

long TheFibonaci(int n)
{
    long []f = new long[n + 2];
    int i;
    f[0] = 1;
    f[1] = 1;
    f[2] = 1;
    for (i = 3; i <= n; i++)
    {
        f[i] = f[i - 1] + f[i - 2];
    }
    return f[n];
}