1 #include <bits/stdc++.h> 2 #define _for(i,a,b) for(int i = (a);i < b;i ++) 3 #define _rep(i,a,b) for(int i = (a);i > b;i --) 4 typedef long long ll; 5 using namespace std; 6 inline ll read() 7 { 8 ll ans = 0; 9 char ch = getchar(), last = ' '; 10 while(!isdigit(ch)) last = ch, ch = getchar(); 11 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar(); 12 if(last == '-') ans = -ans; 13 return ans; 14 } 15 inline void write(ll x) 16 { 17 if(x < 0) x = -x, putchar('-'); 18 if(x >= 10) write(x / 10); 19 putchar(x % 10 + '0'); 20 } 21 22 int n; 23 int a,b; 24 int main() 25 { 26 n = read(); 27 int rnt = 0; 28 _for(i,0,n) 29 { 30 a = read(); 31 if(a>b) 32 rnt += a-b; 33 b = a; 34 } 35 write(rnt); 36 37 38 return 0; 39 }