bash - Calculating the sum of every third column from many files -

i have many files 3 columns in form of:

 file1 | file2  1 0 1  | 1 0 2  2 3 3  | 2 3 7  3 6 2  | 3 6 0  4 1 0  | 4 1 3  5 2 4  | 5 2 1

first 2 columns same in each file. want calculate sum of 3 columns every file receive this:

1 0 3  2 3 10  3 6 2  4 1 3  5 2 5

for 2 files awk 'fnr==nr { _a[fnr]=$3;} nr!=fnr { $3 += _a[fnr]; print; }' file* work (i found solution via google). how change on many files?

since first 2 columns same in each file:

awk 'nr==fnr{b[fnr]=$1 fs $2;}{a[fnr]+=$3}end{for(i=1;i<=length(a);i++){print b[i] fs a[i];}}' file*

array a used have cumulative sum of 3rd column of files. array b used 1st , 2nd column values in end, print contents of array a , b

RT