How to restrict vpasolve() to only integer solutions (MATLAB)

Question

I'm trying to restrict my solution using vpasolve() to only integers but I can't seem to find any equation or parameter that does that. Here is the code below if it helps, the variable I'm trying to restrict is N. Any guidance would be much appreciated.

clc
clear

syms t L S N
height = 0.7;
width = 0.1;
Tdiff = 100;
h = 17;
Qmult = 6;
eff = 0.7;
k = 45;


EQN1 = height==N*(t+S);
m = ((2*height)/(k*t))^0.5;
Lc = L+t/2;
EQN2 = eff==(tanh(m*Lc)/(m*Lc));
EQN3 = Qmult * h*(width*height)*Tdiff==(eff*h*(2*3*Lc)*(Tdiff)*N)+(h*(width*(height-N*t))*(Tdiff));
EQN4 = 0.5== m*L;

vpasolve([EQN1, EQN2, EQN3, EQN4], [t L S N], [0.005 0.3 0.35 60])

I tried using different solve functions and different init parameters but nothing seems to help.