for j in range(0,20):
for poss in ['', 'i386', 'x64'] :
path=os.path.join(rpath,"R-%i.%i.%i" % (maj, i, j),'bin',poss,'R.exe')
for j in range(0,20):
for poss in ['', 'i386', 'x64'] :
path=os.path.join(rpath,"R-%i.%i.%i" % (maj, i, j),'bin',poss,'R.exe')