func_code_string: #include <bits/stdc++.h>   using namespace std;   typedef long long ll;   #define mod 1000000007      int main(){       int n;cin>>n;       int summ = 0;       while(n>9){           int summ = 0;           while(n>9){               summ = summ + n%10;               n = n/10;           }           summ = summ + n;           n = summ;       }       cout<<n;       return 0;   }   