//if groupB is written to file it is above buffer size so read and write to new merged file
if (wroteOutPut[groupIDB]) {
string fileName2 = distFile + "." + toString(groupIDB) + ".temp";
//if groupB is written to file it is above buffer size so read and write to new merged file
if (wroteOutPut[groupIDB]) {
string fileName2 = distFile + "." + toString(groupIDB) + ".temp";