def procedure1():
    print("debut procedure 1")
    print("fin procedure 1")
    
def procedure2():
    print("debut procedure 2")
    procedure1()
    print("fin procedure 2")
    
def procedure3():
    print("debut procedure 3")
    procedure1()
    procedure2()
    print("fin procedure 3")
    
print("debut main")
procedure2()
procedure3()
print("fin main")