import sysa = list(input())[::-1]
s = ""
cnt = 0
for v in a:cnt += 1s += vif cnt%3==0:s += ','
print(s.rstrip(',')[::-1])
import sys
import functools
@functools.cache
def dfs(u):if u==1 or u==2:return ureturn dfs(u-1)+dfs(u-2)
print(dfs(int(input())))
class Solution {bool hash[14] = { 0 };public:bool IsContinuous(vector<int>& numbers) {int maxVal = 0, minVal = 14;for (auto x : numbers) {if (x) {if (hash[x]) return false;hash[x] = true;maxVal = max(maxVal, x);minVal = min(minVal, x);}}return maxVal - minVal <= 4;}
};