void merge(vll &L, vll &R, vll &A){
ll i=0,j=0,k=0,iL,jL;
iL = L.size();
jL = R.size();
while(i<iL && j<jL ){
if(L[i]<=R[j]){
A[k] = L[i];
i++;
}
else if(R[j]<=L[i]){
A[k] = R[j];
j++;
}
k++;
}
while(i<iL){
A[k] = L[i];
i++;
k++;
}
while(j<jL){
A[k] = R[j];
j++;
k++;
}
return;
}
vll matmul(const vll &A, const vll &B) {
int m = A.size();
int n = B[0].size();
int x = B.size();
vll C(m, vector<long long>(n, 0));
for (int i=0; i<m; ++i) {
for (int j=0; j<n; ++j) {
for (int k=0; k<x; ++k) {
C[i][j] = (C[i][j] + A[i][k]*B[k][j]) % mod;
}
}
}
return C;
}
vll mul(const vll & va, const vll & vb) {
int len = 32 - __builtin_clz(std::max(va.size(), vb.size()) - 1);
len = 1 << (len + 1);
vcd a(len), b(len);
for (int i = 0; i < (int)va.size(); i++) a[i] = cd(va[i], 0);
for (int i = 0; i < (int)vb.size(); i++) b[i] = cd(vb[i], 0);
a = fft(a);
b = fft(b);
for (int i = 0; i < len; i++) {
double real = a[i].real() * b[i].real() - a[i].imag() * b[i].imag();
a[i].imag() = a[i].imag() * b[i].real() + b[i].imag() * a[i].real();
a[i].real() = real;
}
a = fft(a, true);
vll res(len);
for (int i = 0; i < len; i++) res[i] = (long long)(a[i].real() + 0.5);
return res;
}
void all( vll& v, vll& l )
{
for( int i = 0; i < v.size(); ++i )
{
vll tmp, comb;
for( vlli j = l.begin(); j != l.end(); ++j )
tmp.push_back( *j + v[ i ] );
for( vlli m = l.begin(), n = tmp.begin(); m != l.end() || n != tmp.end(); )
comb.push_back( n == tmp.end() || m != l.end() && *m <= *n? *m++ : *n++ );
l.swap( comb );
}
}
ll solve(vll dat)
{
int sz=dat.size();
for(int i=1;i<sz;i++)
{
if(i==1)
dat[i]=max(dat[i-1], dat[i]);
else
dat[i]=max(dat[i-1], dat[i]+dat[i-2]);
}
return dat[sz-1];
}
vll matexp(vll A, int n) {
int m = A.size();
vll ret = matunit(m);
while (n > 0) {
if (n & 1) {
ret = matmul(ret, A);
}
A = matmul(A, A);
n >>= 1;
}
return ret;
}
int main()
{
LL i,n,ans,k;
while(cin>>k>>str)
{
cnt.pb(0);
for(i=0; i<str.size(); i++)
{
if(str[i]=='1') cnt.pb(i+1);
}
cnt.pb(str.size()+1);
if(k>cnt.size()-2)
{
pr1(0);
continue;
}
ans=0;
if(k==0)
{
for(i=1;i<cnt.size();i++)
{
n=cnt[i]-cnt[i-1]-1;
ans+=n*(n+1)/2;
}
}
else
{
for(i=1; i<cnt.size()-k; i++)
{
ans+=(cnt[i]-cnt[i-1])*(cnt[i+k]-cnt[i+k-1]);
}
}
pr1(ans);
}
return 0;
}
vll merge_sort(vll S){
vll tempL,tempR;
ll len = S.size();
if(len < 2 )
return S; // array is already sorted. Base case
rep(i,len/2)
tempL.pub(S[i]);
repk(i,len/2,len)
tempR.pub(S[i]);
tempL = merge_sort(tempL);
tempR = merge_sort(tempR);
merge(tempL,tempR,S);
return S;
}
vll matadd(const vll &A, const vll &B) {
int m = A.size();
int n = A[0].size();
vll C(m, vector<long long>(n, 0));
for (int i=0; i<m; ++i) {
for (int j=0; j<n; ++j) {
C[i][j] = A[i][j] + B[i][j];
if (C[i][j] >= mod) {
C[i][j] -= mod;
}
}
}
return C;
}
int main()
{
LL a,b,i,k;
bool flag;
gen();
while(scanf("%lld %lld",&a,&b)!=EOF)
{
flag=true;
for(i=0; i<cont.size() && cont[i]<=a+b; i++)
{
if(cont[i]>=a && cont[i]<=a+b) printf("%lld\n",cont[i]),flag=false;
}
if(flag) printf("None\n");
}
return 0;
}
void init()
{
int i=0 , j;
LL pnum=0 , p=1;
sll st;
sll::iterator it;
for(i=0; i<plen; i++)
{
pnum = prm[i];
for(j=2; j<=40; j++)
{
//pnum = power(prm[i] , j);
p=1;
for(int k=1; k<=j; k++)
{
p*=pnum;
if(p > mxhigh) break;
}
if(p < mxhigh)
{
st.insert(p);
}
}
}
//cerr << st.size();
for(it=st.begin() ; it!=st.end() ; ++it)
{
v.push_back(*it);
}
//for(i=0; i<100; i++) cout << v[i] << " ";
//cout << v.size();
//cout << v[v.size()-1];
vlen = v.size();
}
int deal(){
weight.clear();
cin >> buf;
int depth = 0;
ll tmp;
for (string::iterator ii = buf.begin(); ii != buf.end(); ii++){
switch (*ii){
case '[':
{
depth++;
}break;
case ']':
{
depth--;
}break;
case ',':break;
default:
{
tmp = 0;
while ('0' <= *ii && *ii <= '9') tmp = tmp * 10 + *ii - '0', ii++;
ii--;
weight.push_back(tmp << depth);
}
}
}
sort(weight.begin(), weight.end());
int len = weight.size();
int best = 0, cur = 1;
weight.push_back(-1);
for (int i = 0; i < len; i++){
if (weight[i + 1] != weight[i]){
best = max(best, cur);
cur = 1;
}
else cur++;
}
return len - best;
}
static vll karatsubaMultiply(const vll &a, const vll &b) {
int n = a.size();
vll res(n + n);
if (n <= 32) {
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
res[i + j] += a[i] * b[j];
return std::move(res);
}
int k = n >> 1;
vll a1(a.begin(), a.begin() + k);
vll a2(a.begin() + k, a.end());
vll b1(b.begin(), b.begin() + k);
vll b2(b.begin() + k, b.end());
vll a1b1 = karatsubaMultiply(a1, b1);
vll a2b2 = karatsubaMultiply(a2, b2);
for (int i = 0; i < k; i++)
a2[i] += a1[i];
for (int i = 0; i < k; i++)
b2[i] += b1[i];
vll r = karatsubaMultiply(a2, b2);
for (int i = 0; i < (int)a1b1.size(); i++)
r[i] -= a1b1[i];
for (int i = 0; i < (int)a2b2.size(); i++)
r[i] -= a2b2[i];
for (int i = 0; i < (int)r.size(); i++)
res[i + k] += r[i];
for (int i = 0; i < (int)a1b1.size(); i++)
res[i] += a1b1[i];
for (int i = 0; i < (int)a2b2.size(); i++)
res[i + n] += a2b2[i];
return std::move(res);
}
