Problem:
Score : 100 points

Problem Statement

There are two rectangles.
The lengths of the vertical sides of the first rectangle are A, and the lengths of the horizontal sides of the first rectangle are B.
The lengths of the vertical sides of the second rectangle are C, and the lengths of the horizontal sides of the second rectangle are D.

Print the area of the rectangle with the larger area.
If the two rectangles have equal areas, print that area.

Constraints

All input values are integers.

1≤A≤10^4

1≤B≤10^4

1≤C≤10^4

1≤D≤10^4

Input

The input is given from Standard Input in the following format:

A B C D

Output

Print the area of the rectangle with the larger area.
If the two rectangles have equal areas, print that area.

Sample Input 1

3 5 2 7

Sample Output 1

15

The first rectangle has an area of 3×5=15, and the second rectangle has an area of 2×7=14.
Thus, the output should be 15, the larger area.

Sample Input 2

100 600 200 300

Sample Output 2

60000

Solution in Rust (1.15.1) (judge verdict: Accepted)

fn main() {
    let a: i32 = read();
    let b: i32 = read();
    let c: i32 = read();
    let d: i32 = read();

    let s1 = a*b;
    let s2 = c*d;
    println!("{}", max(s1, s2));
}

// 以下関数

use std::io::*;
use std::str::FromStr;
pub fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

pub const MOD: u64 = 10e9 as u64 + 7;

pub fn is_prime(n: i32) -> bool {
    if n < 2 {
        return false;
    } else if n == 2 {
        return true;
    }
    let mut i = 2;
    while i * i < n {
        if n % i == 0 {
            return false;
        } else {
            i += 1;
            continue;
        }
    }
    true
}

pub fn lcm(mut n: i32, mut m: i32) -> i32 {
    n = if n > m { m } else { n };
    m = if n > m { n } else { m };
    let mut i = n;
    while i % m != 0 {
        i += n;
    }
    i
}

pub fn abs(n: i32) -> i32 {
    if n >= 0 {
        n
    } else {
        -n
    }
}

pub fn max(n: i32, m: i32) -> i32 {
    if n >= m {
        n
    } else {
        m
    }
}

pub fn min(n: i32, m: i32) -> i32 {
    if n <= m {
        n
    } else {
        m
    }
}