function rewardContributors(address[] _contributors, uint256[] _tokenAmounts) external onlymanyowners(sha3(msg.data)) {
        if(isContributorsRewarded || _contributors.length != _tokenAmounts.length) {
            return;
        }

        uint256 sum = 0;
        for (uint64 i = 0; i < _contributors.length; i++) {
            require(_contributors[i] != 0x0);
            sum = sum.add(_tokenAmounts[i]);
            token.transfer(_contributors[i], _tokenAmounts[i]);
        }
        require(sum == token.totalSupply().mul(20).div(100));
        isContributorsRewarded = true;
    }