cn = 0; forprime( i = 1, 10^8, ze = 0; if (length(digits(i,3))%2 == 0, for (j = 1, length(digits(i,3)), if (digits(i,3)[j] == 2, ze += 1)); if (ze == length(digits(i,3))/2, cn += 1)) ); print(cn)