72-x=40
x=72-40=32
k+35=60
k=60-35=25
39+d=59
d=59-39=20
56-d=31
d=56-31=25
x=72-40
x=32
k=60-35
k=25
d=59-39
d=20
d=56-31
d=25
72-x=40
x=72-40=32
k+35=60
k=60-35=25
39+d=59
d=59-39=20
56-d=31
d=56-31=25
72-x=40
x=72-40
x=32
k+35=60
k=60-35
k=25
39+d=59
d=59-39
d=20
56-d=31
d=56-31
d=25