# include <iostream> # include <algorithm> using namespace std ; long long a [1919810] ; long long b [1919810] ; int main ( ) { long long n ; cin >> n ; long long cnt = 0 ; for ( long long i = 1 ; i <= n ; i ++ ) { cin >> a [i] ; } for ( long long i = 1 ; i <= n ; i ++ ) { if ( b [i] < a [i] ) { cnt += a [i] - b [i] ; for ( long long j = i + 1 ; j <= n ; j ++ ) { b [j] += a [i] - b [i] ; } } else if ( b [i] > a [i] ) { cnt += b [i] - a [i] ; for ( long long j = i + 1 ; j <= n ; j ++ ) { b [j] -= b [i] - a [i] ; } } } cout << cnt << endl ; return 0 ; }