Hi,

I do have a problem to write a Fortran program to select data from a huge data set as follows:

1.500D+00 1.000D+06 3.000D+06 5.000D+06 7.000D+06 9.000D+06 1.100D+07 1.300D+07
1.500D+07 1.700D+07 1.900D+07 2.100D+07 2.300D+07 2.500D+07 2.700D+07 2.900D+07
3.100D+07 3.300D+07 3.500D+07 3.700D+07 3.900D+07 4.100D+07 4.300D+07 4.500D+07
4.700D+07 4.900D+07 5.100D+07 5.300D+07 5.500D+07 5.700D+07 5.900D+07 6.100D+07
1.750D+08 1.770D+08 1.790D+08 1.810D+08

2.000D+00 1.000D+06 3.000D+06 5.000D+06 7.000D+06 9.000D+06 1.100D+07 1.300D+07
1.500D+07 1.700D+07 1.900D+07 2.100D+07 2.300D+07 2.500D+07 2.700D+07 2.900D+07
3.100D+07 3.300D+07 3.500D+07 3.700D+07 3.900D+07 4.100D+07 4.300D+07 4.500D+07
4.700D+07 4.900D+07 5.100D+07 5.300D+07 5.500D+07 5.700D+07 5.900D+07 6.100D+07
1.750D+08 1.770D+08 1.790D+08 1.810D+08

2.500D+00 1.000D+06 3.000D+06 5.000D+06 7.000D+06 9.000D+06 1.100D+07 1.300D+07
1.500D+07 1.700D+07 1.900D+07 2.100D+07 2.300D+07 2.500D+07 2.700D+07 2.900D+07
3.100D+07 3.300D+07 3.500D+07 3.700D+07 3.900D+07 4.100D+07 4.300D+07 4.500D+07
4.700D+07 4.900D+07 5.100D+07 5.300D+07 5.500D+07 5.700D+07 5.900D+07 6.100D+07
1.750D+08 1.770D+08 1.790D+08 1.810D+08
.....
....
....

The data consists of blocks (without spaces), the number of blocks is not known, each block contains 36 numbers, my problem is to select certain numbers from each block say B1(1)B1(20),B1(33) and put all data from all blocks under each other as:
B1(1) B1(20) B1(33)
B2(1) B2(20) B2(33)
B3(1) B3(20) B3(33)
..................

Can anybody help please,

Thanks in advance