讲解视频

#include<bits/stdc++.h>
using namespace std;
int main(){
	char s[21];
	int ans=0;
	cin>>s;
	for(int i=0;i<strlen(s);i++){
		if(s[i]>='0' and s[i]<='9')
			ans++;
	}
	cout<<ans;
	return 0;
}