#include <iostream>


using namespace std;
#define SAY_YES cout << "YES" << endl;
#define SAY_Yes cout << "Yes" << endl;
#define SAY_NO cout << "NO" << endl;
#define SAY_No cout << "No" << endl;
#define IFYES(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "YES" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "NO" << endl;  \
    }
#define IFYes(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "Yes" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "No" << endl;  \
    }
#define IFyes(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "yes" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "no" << endl;  \
    }
#define DEBUG_OUTPUT_ARRAY(XXX, ONE)                            \
    for (int i = 0; i < (ONE); i++)                             \
    {                                                           \
        cout << "DEBUG: i = " << i << " -> " << XXX[i] << endl; \
    }
#define DEBUG_OUTPUT_ARRAY2(XXX, ONE, TWO)                             \
    for (int i = 0; i < (ONE); i++)                                    \
    {                                                                  \
        cout << "<<< i = " << i << " >>>" << endl;                     \
        for (int j = 0; j < (TWO); j++)                                \
        {                                                              \
            cout << "DEBUG: j = " << j << " -> " << XXX[i][j] << endl; \
        }                                                              \
    }
#define DEBUG_OUTPUT_ARRAY2_BOX(XXX, ONE, TWO) \
    for (int i = 0; i < (ONE); i++)            \
    {                                          \
        cout << i << "  ";                     \
        for (int j = 0; j < (TWO); j++)        \
        {                                      \
            cout << XXX[i][j] << " ";          \
        }                                      \
        cout << endl;                          \
    }

typedef pair<long long int, long long int> pll;
typedef pair<long long int, pll> lpll;

const long long int mod = 1000000007;
const long long int INF = 1e18;
const long double PI=3.14159265358979323; 
//const long long int pl=1000000;

long long int N,M,h[2000]={},w[2000]={},memo[1600000]={},res=0;
int main(){


    
    cin>>N>>M;
    while(N!=0){
        for(long long int i = 1; i <= N; i++){
            cin>>h[i];
            h[i]+=h[i-1];
        }

        for(long long int i = 1; i <= M; i++){
            cin>>w[i];
            w[i]+=w[i-1];
        }

        for(long long int i = 0; i < 1500500; i++){
            memo[i]=0;
        }
        for(long long int i = 1; i <= N; i++){
            for(long long int j = 0; j < i; j++){
                memo[h[i]-h[j]]++;
            }
        }
        for(long long int i = 1; i <= M; i++){
            for(long long int j = 0; j < i; j++){
                res+=memo[w[i]-w[j]];
            }
        }
        cout<<res<<endl;
        res=0;
        cin>>N>>M;
    }
    
}




Measured memory_bytes: 14704