// Original: https://github.com/tanakh/competitive-rs #[allow(unused_macros)] macro_rules! input { (source = $s:expr, $($r:tt)*) => { let mut iter = $s.split_whitespace(); let mut next = || { iter.next().unwrap() }; input_inner!{next, $($r)*} }; ($($r:tt)*) => { let stdin = std::io::stdin(); let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock())); let mut next = move || -> String{ bytes .by_ref() .map(|r|r.unwrap() as char) .skip_while(|c|c.is_whitespace()) .take_while(|c|!c.is_whitespace()) .collect() }; input_inner!{next, $($r)*} }; } #[allow(unused_macros)] macro_rules! input_inner { ($next:expr) => {}; ($next:expr, ) => {}; ($next:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($next, $t); input_inner!{$next $($r)*} }; ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => { let mut $var = read_value!($next, $t); input_inner!{$next $($r)*} }; } #[allow(unused_macros)] macro_rules! read_value { ($next:expr, ( $($t:tt),* )) => { ( $(read_value!($next, $t)),* ) }; ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, [ $t:tt ]) => { { let len = read_value!($next, usize); (0..len).map(|_| read_value!($next, $t)).collect::>() } }; ($next:expr, chars) => { read_value!($next, String).chars().collect::>() }; ($next:expr, bytes) => { read_value!($next, String).into_bytes() }; ($next:expr, usize1) => { read_value!($next, usize) - 1 }; ($next:expr, $t:ty) => { $next().parse::<$t>().expect("Parse error") }; } mod util { #[allow(dead_code)] pub fn chmin(x: &mut T, y: T) -> bool where T: PartialOrd + Copy, { *x > y && { *x = y; true } } #[allow(dead_code)] pub fn chmax(x: &mut T, y: T) -> bool where T: PartialOrd + Copy, { *x < y && { *x = y; true } } /// 整数除算切り上げ #[allow(dead_code)] pub fn roundup(a: i64, b: i64) -> i64 { (a + b - 1) / b } #[allow(dead_code)] pub fn ctoi(c: char) -> i64 { c as i64 - 48 } } #[allow(unused_imports)] use util::*; #[allow(unused_imports)] use std::cmp::{max, min}; #[allow(unused_imports)] use std::collections::{BTreeMap, BTreeSet, BinaryHeap, VecDeque}; fn main() { input! { a:i64,b:i64,c:i64 } let mut ok = c; let mut ng = 1; let mut ans = 0; while (ok - ng).abs() > 1 { let multnum = count_multiple_lr(ng, ok, a, 0); let total = (ok - ng + 1) + ((b - 1) * multnum); // println!("ok:{}, ng:{}, multnum:{}, total:{}", ok, ng, multnum, total); let mid = (ok + ng) / 2; if total >= c { ans = ok; ok = mid; } else { ng = mid; // break; } } println!("{}", ans); } /// 半開区間[0,R) の間の数でdivで割ったときの剰余がmである個数 pub fn count_multiple(r: i64, div: i64, m: i64) -> i64 { if r == 0 { return 0; } let mut res = r / div; if m < r % div && 0 <= m { res += 1; } res } /// 閉区間[L,R] の間の数でdivで割ったときの剰余がmである個数 pub fn count_multiple_lr(l: i64, r: i64, div: i64, m: i64) -> i64 { // [0,r+1) - [0,l) = [l,r] count_multiple(r + 1, div, m) - count_multiple(l, div, m) }