#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int v, c; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

int dp[31][31][31][31], _dp[31][31][31][31];

int main() {
	string S; cin >> S;
	int sum = 0;
	for (int i = 0; i < S.length(); i++) {
		char c = S[i];
		if (c >= '0' && c <= '9')
			sum += c - '0';
	}
	cout << sum << endl;
}