#include <cstdio>
#include <iostream>
using namespace std;
int n,a[100010],ans;
int main(){
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d",&a[i]);
if(a[i]>a[i-1])ans+=a[i]-a[i-1];
}
printf("%d\n",ans);
return 0;
}
原文：http://www.cnblogs.com/codetogether/p/7652131.html