Python example to find Student Grade

mark=int(input("Enter Mark:"))
if(mark>95 and mark<=100):
    print("O Grade")
elif(mark>90 and mark<=95):
    print("A grade")
elif(mark>80 and mark<91):
    print("B Grade")
elif(mark>70 and mark<81):
    print("C Grade")
elif(mark>60 and mark<71):
    print("D Grade")
elif(mark>49 and mark<61):
    print("E Grade")
elif(mark>=0 and mark<50):
    print("F Grade")
else:
    print("Invalid Mark")