#include<bits/stdc++.h> using namespace std; int main(){ int n;cin>>n; int a[n+1]; for(int i=1;i<=n;i++) cin>>a[i]; int sum=0; for(int i=1;i<=n;i++){ if(i==n) break; if(a[i]<a[i+1]){ //cout<<a[i+1]<<"-"<<a[i]<<"="<<a[i+1]-a[i]<<endl; sum+=a[i+1]-a[i]; } } cout<<sum; }