#include<bits/stdc++.h>
using namespace std;
string a;
int main(){
	int sum=0;
	cin>>a;
	int la=a.size();
	for (int i =0;i<la;i++){
		sum+=a[i]-'0';
	}
	cout<<sum;
	return 0;
}

#include<bits/stdc++.h> using namespace std; string s; int main(){ cin>>s; long long sum=0; for(int i=0; i<s.size();i++){ sum=sum+s[i]-'0'; } cout<<sum; return 0; }

#include<bits/stdc++.h>
using namespace std; 
string s; 
int main(){ 
cin>>s; 
long long sum=0; 
for(int i=0; i<s.size();i++){ 
sum=sum+s[i]-'0'; 
} 
cout<<sum; return 0; 
}

#include<bits/stdc++.h> using namespace std; int main(){ char a[210]; int i,s=0; cin>>a; for(i=0;i<strlen(a);i++){ s=s+(a[i]-48); } cout<<s; return 0; }

using namespace std;
string s;
int main(){
cin>>s;
long long sum=0;
for(int i=0; i<s.size();i++){
	sum=sum+s[i]-'0';
}
cout<<sum;
	return 0;
}

https://theuselessweb.com https://puginarug.com https://optical.toys/thatcher-effect/ https://memory.toys/classic/medium/ https://maze.toys/mazes/mini/daily/ https://cursoreffects.com/ 好玩网站

给个题解，求求了！