Change numbers if unique values found

hello



i have text in range d2:d500 (text only)

and i want to add numbers to range a2:a500 but with conditon

D2 = AHSAAAN..........A2 = 1
D3 = AHSAAAN..........A3 = 2
D4 = AHSAAAN..........A4 = 3
D5 = AHSAAAN..........A5 = 4
D6 = AAAKIB..........A6 = 1...............Change number if text found unique one
D7 = AAAKIB..........A7 = 2
D8 = BHURA..........A8 = 1
D9 = DANISH..........A9 = 1
D10 = HAROON..........A10 = 1
D11 = HAROON..........A11 = 2
D12 = HAROON..........A12 = 3
D13 = ZAID..........A13 = 7


change number sequence if found unique Entry

thanx

perfect once again