4. A, B, and C went to the orchard to pick oranges, and they picked a total of 108 oranges. A first gave half of his oranges to B, then B gave $\frac{1}{5}$ of his oranges at that time to C, and finally C gave $\frac{1}{7}$ of his oranges at that time to A. If at this point the three of them had the same number of oranges, how many oranges did each of them initially pick?
4. At first, A, B, and C collected 60, 15, and 33 oranges, respectively.

Since in the end, each of the three had $108 \div 3=36$ oranges, before C gave oranges to A,
C had $36 \div\left(1-\frac{1}{7}\right)=42$ oranges,
A had $36 \times 2-42=30$ oranges.
Thus, before B gave oranges to C,
B had $36 \div\left(1-\frac{1}{5}\right)=45$ oranges,
C had $36+42-45=33$ oranges.
Therefore, before A gave oranges to B, i.e., initially, A collected $30 \times 2=60$ oranges, B collected $30+45-60=$ 15 oranges, and C collected 33 oranges.