#include <bits/stdc++.h>
using namespace std;
const int N = 500;
char s[N];
bool check(char c) {
return c >= '0' && c <= '9';
}
int main() {
scanf("%s", s);
int l = -1, r = -1;
int n = strlen(s);
int left = 0, right = -1;
while (left < n) {
if (check(s[left])) {
int ll = left;
while (left < n && check(s[left]))++left;
right = left;
if (right - ll > r - l) {
l = ll, r = right;
}
}
++left;
}
for (int i = l; i < r; ++i)cout << s[i];
return 0;
}