??

src/main.rs

@@ -0,0 +1,30 @@
+extern crate num_bigint;
+// extern crate num_traits;
+
+use num_bigint::BigUint;
+
+
+fn main()
+{
+    let mut num = BigUint::from(0 as u8);
+    num = num + 277777788888899u128;
+
+    println!("{:?}", test(num));
+}
+
+fn test(input: BigUint) -> u8 {
+    let mut n = factorize(input);
+    let mut counter = 1;
+    while (n.to_str_radix(10).chars().count() > 0) {
+        n = factorize(n);
+        println!("n: {:?}", n);
+        counter += 1;
+    }
+    return counter;
+}
+
+fn factorize(input: BigUint) -> BigUint {
+    let string = input.to_str_radix(10);
+    let numbers: Vec<u8> = string.chars().map(|x| x as u8 - 48).collect();
+    numbers.into_iter().product::<BigUint>()
+}