sdef1 3Mev @ 0 6 0
10 1 -8.0  -1    imp:n=1
20 0       +1    imp:n=0

1 RPP  -5.0  +5.0  -5.0  +5.0  -5.0  +5.0 

m1  26000 1
sdef pos = 0 0 0  erg=1
print
nps 100000