10929.cpp

#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>

typedef unsigned int uint;
typedef long long int64;
typedef unsigned long long uint64;

using namespace std;

int main(){
    while(true){
                string str;
                cin>>str;
                if(str=="0")
                            break;
                int len = str.length(), i;
                int64 sum=0;
                for(i=0; i<len; i++){
                         if(i%2 == 0)
                                sum += (str[i]-'0');
                         else
                             sum -= (str[i]-'0');
                }
                if(sum < 0)
                       sum *= -1;
                if(sum%11 == 0)
                          cout<<str<<" is a multiple of 11.\n";
                else
                    cout<<str<<" is not a multiple of 11.\n";
    }
    return 0;
}