#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
#define Mohab ios_base::sync_with_stdio(false); cin.tie(nullptr);
#define el '\n'

void RRR() {
 string s; cin>>s;
 ll sum=s[0]-'0';
 for (int i=1; i<s.size(); i++){
     sum+=abs((s[i]-'0') - (s[i-1]-'0'));
 }
 cout<<sum-1;
}

signed main() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    Mohab
    int T = 1;
//    cin >> T;
    while (T--)
        RRR();
}