找了半天，没错

#include<iostream>
using namespace std;
int main(){
    int a,b,c=0,sum=0;
    cin>>a;
    for(int i=a;i<=a;i++){
        cin>>b;
        if(b%10==3||b%3==0){
            c+=i;
            sum+=1;
        }
    }cout<<c<<" "<<sum;
    return 0;
}