#include<bits/stdc++.h> using namespace std; int main() { int n,price[10001],m=0; cin>>n; for(int i=1;i<=n;i++) { cin>>price[i]; } for(int i=1;i<=n;i++) { if(price[i+1]-price[i]>=0&&i+1<=n) { m+=price[i+1]-price[i]; } else { continue; } } cout<<m; return 0; }