I have a dataset annotated by three people, so now I have three files. This dataset is about tweets annotation. How can I combine this dataset into one file for further processing. The data set is an excel file and contains five columns:

i have a dataset annoted by three person so now i have three files this dataset is about tweets annotation .How to combine this dataset in one file for further processing.the data set is inn excel file and contains five coloumns name tweet id PPP,PTI,PMLN, full text the annotaions is done on pti,pmln each cououm of annotation is 0.1,-1 value