<filename>AtC_Beg_Con_081-090/ABC090/A.py
p = input()
q = input()
r = input()

print(p[0] + q[1] + r[2])
<filename>AtC_Beg_Con_081-090/ABC090/A.py
p = input()
q = input()
r = input()

print(p[0] + q[1] + r[2])