# your code goes here
"""
from collections import defaultdict
n = int(input())
arr = list(map(int, input().split()))
 
def findMaxPoints(maxNum, numFreqMap, currNum, dpArr):
    if currNum <= 0:
        return 0
    if dpArr[currNum] != -1:
        return dpArr[currNum]
    dpArr[currNum] = max(
        (numFreqMap.get(currNum, 0) * currNum) + findMaxPoints(maxNum, numFreqMap, currNum - 2, dpArr),
        findMaxPoints(maxNum, numFreqMap, currNum - 1, dpArr)
    )
    return dpArr[currNum]
 
numFreqMap = defaultdict(int)
maxNum = 0
for i in arr:
    numFreqMap[i] += 1
    maxNum = max(maxNum, i)
dpArr = [-1] * (maxNum + 1)
print(findMaxPoints(maxNum, numFreqMap, maxNum, dpArr))
"""

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