Problem:
Score : 100 points

Problem Statement

You are parking at a parking lot. You can choose from the following two fee plans:

Plan 1: The fee will be A×T yen (the currency of Japan) when you park for T hours.

Plan 2: The fee will be B yen, regardless of the duration.

Find the minimum fee when you park for N hours.

Constraints

1≤N≤20

1≤A≤100

1≤B≤2000

All input values are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

When the minimum fee is x yen, print the value of x.

Sample Input 1

7 17 120

Sample Output 1

119

If you choose Plan 1, the fee will be 7×17=119 yen.

If you choose Plan 2, the fee will be 120 yen.

Thus, the minimum fee is 119 yen.

Sample Input 2

5 20 100

Sample Output 2

100

The fee might be the same in the two plans.

Sample Input 3

6 18 100

Sample Output 3

100

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

extern crate core;

use std::io::{self, Read};
use std::cmp;

fn main() {
    let mut input = String::new();
    io::stdin().read_to_string(&mut input).unwrap();
    let output = run(input);
    println!("{}", output);
}

fn run(input: String) -> String {
    let list: Vec<i32> = input
        .split_whitespace()
        .map(|x| x.parse::<i32>().unwrap())
        .collect();
    let n = list[0];
    let a = list[1];
    let b = list[2];

    cmp::min(n * a, b).to_string()
}

#[test]
fn test() {
    let tests = vec![
        ("7 17 120", "119"),
        ("5 20 100", "100"),
        ("6 18 100", "100"),
    ];
    for (i, &(input, output)) in tests.iter().enumerate() {
        println!("test:{}", i);
        assert_eq!(run(input.to_string()), output.to_string());
    }
}