// coin stake reward
int64_t GetProofOfStakeReward(const CBlockIndex* pindexPrev, int64_t nCoinAge, int64_t nFees)
{
    int64_t nSubsidy = 0 * COIN;
if (pindexBest->nHeight+1 > 1000 && pindexBest->nHeight+1 <= 20000)
{
nSubsidy = 10 * COIN;
}
else if (pindexBest->nHeight+1 > 20000 && pindexBest->nHeight+1 <= 100000)
{
nSubsidy = 5 * COIN;
}
else if (pindexBest->nHeight+1 > 100000 && pindexBest->nHeight+1 <= 500000)
{
nSubsidy = 3 * COIN;
}
else if (pindexBest->nHeight+1 > 500000 && pindexBest->nHeight+1 <= 800000)
{
nSubsidy = 2 * COIN;
}
else if (pindexBest->nHeight+1 > 800000)
{
nSubsidy = 1 * COIN;
}

    return nSubsidy + nFees;
}