Could You consider the conjecture as follows to make additional proposals for polymath project?
Let $A, B, C$ be three positive integer numbers such that $A+B=C$ with $\gcd(A, B, C) = 1$. By Fundamental theorem of arithmetic we write:
$A=a_1^{x_1}a_2^{x_2}...a_n^{x_n}$,
$B=b_1^{y_1}b_2^{y_2}...b_m^{y_m}$,
$C=c_1^{z_1}c_2^{z_2}...c_k^{z_k}$
Let $d=\min\{x_i, y_j, z_h \}$ where $1 \le i \le n, 1\ \le j \le m, 1\le h \le k$ then:
My conjecture: $$d \le 5$$
The conjecture in here
PS: I researched about one hundred papers, in any case $h \le 3$?