a = int(input()) b = input() ans = 0 if b == ('n'): if a<=1000: ans = ans+8 else: if (a-1000)%500==0: ans = ans+8+((a-1000)//500)*4 else: ans = ans+8+((a-1000)//500+1)*4 else: if a<=1000: ans = ans+8+5 else: if (a-1000)%500==0: ans = ans+8+((a-1000)//500)*4+5 else: ans = ans+8+((a-1000)//500+1)*4+5 print(ans)