#include <iostream> #include <cstdio> using namespace std; int main() { char s[256]; int n=0; cin>>s; cin.getline(s,256); for (int i=0;s[i]!='\0';i++){ if (s[i]>='0' && s[i]<='9'){ n=n+1; } } cout<<n; return 0; }