#include <cstdio>

int main()
{
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    int N, M, piante[1000001];
    int sx = 0, dx = -1;
    int sum = 0;
    int cont = 0;
    scanf("%d %d", &M, &N);

    for(int i = 0; i < N; i++) scanf("%d", piante+i);

    while(dx < N - 1)
    {
    while(sum < M && dx < N -1) sum += piante[++dx];
    while(sum == M && dx < N - 1)
    {
        int tSx = 1, tDx = 1;
        while(piante[sx] == 0 && sx < dx) { tSx++; sx++; }
        while(piante[dx+1] == 0 && dx < N-1) { tDx++; dx++; }
        cont += (tSx*tDx);
        sum -= piante[sx++];
    }
    while(sum > M && sx < dx) sum -= piante[sx++];
    }

    printf("%d\n", cont);

    return 0;
}