string organizingContainers(vector<vector<int>> container) {
    int sizeRow = container.size();
    
    multiset<int> columnSums;
    multiset<int> rowSums;

    vector<int> partialColumnSums(sizeRow, 0);
    for (int i = 0; i < sizeRow; i++) {
        
        int currentRowSum = 0;
        for (int j = 0; j < sizeRow; j++) {
            currentRowSum += container.at(i).at(j);
            partialColumnSums[j] += container.at(i).at(j);
        }
        
        rowSums.insert(currentRowSum);
    }
    
    for (int partialColumnSum : partialColumnSums) {
        columnSums.insert(partialColumnSum);
    }
    
    if (columnSums == rowSums) {
        return "Possible";
    }
    
    return "Impossible";
}