int numDocs = readLine // assuming first number is number of docs

for (int i = 0; i < numDocs; ++i)
{
    string line = readLine
    int docNumber = getFirstNumber(line)
    int numKeywords = getSecondNumber(line)

    for (int j = 0; j < numKeywords; ++j)
    {
        string keyword = readline
        associate keyword with docNumber // however this works
    }
}