[백준] 10707번 : 수도요금 - Dart(다트)

https://www.acmicpc.net/problem/10707

import 'dart:io';
import 'dart:math';
void main(){
    int? a=int.parse(stdin.readLineSync()!);
    int? b=int.parse(stdin.readLineSync()!);
    int? c=int.parse(stdin.readLineSync()!);
    int? d=int.parse(stdin.readLineSync()!);
    int? p=int.parse(stdin.readLineSync()!);
    var sum=p*a;
    var sum1=0;
    if(p<=c) sum1=b;
    else sum1=b+(p-c)*d;
    print(min(sum,sum1));
}