Integrity check failed. 完整性检查失败？这是什么意思？ 代码：

#include <bits/stdc++.h>
#define ll long long
#define MAXN 100007
using namespace std;
ll n;
ll d[MAXN];
ll ans;
int main(){
	scanf("%lld",&n);
	for(int i=1;i<=n;i++){
		scanf("%lld",&d[i]);
	}
	for(int i=1;i<=n;i++){
		if(d[i-1]<d[i]){
			ans+=d[i]-d[i-1];
		}
	}
	printf("%lld",ans);
    return 0;
}