随机刷题终于好了一次

#include <iostream>
#include <cstdio>
using namespace std;
int a[100005];
int main(){
	int n;
	cin >> n;
	long long ct = 0;
	for(int i = 1; i <= n; i++){
		cin >> a[i];
		if(a[i] > a[i - 1]) ct += (a[i] - a[i - 1]);
	}cout << ct;

	return 0;
}