fn pancake(n: i32) -> i32 {
let mut gap = 2;
let mut sum = 2;
let mut adj = -1;
while sum < n {
adj += 1;
gap = gap * 2 - 1;
sum += gap;
}
n + adj
fn main() {
for i in 0..4 {
for j in 1..6 {
let n = i * 5 + j;
print!("p({:2}) = {:2} ", n, pancake(n));
println!();