#include <algorithm>
#include <iostream>
using namespace std;
const int N = 50000;
const int L = 17;
const int N_ = 1 << L;
const int MD = 998244353;
char cc[N * 2 + 2];
int aa[N_], bb[N_];
long long power(long long a, int k) {
long long p = 1;
for ( ; k; k >>= 1) {
if (k & 1)
p = p * a % MD;
a = a * a % MD;
}
return p;
}
void ntt(int *aa, int l, bool inverse) {
int n = 1 << l;
for (int i = 0, j = 1; j < n; j++) {
for (int b = n >> 1; !((i ^= b) & b); b >>= 1)
;
if (i < j)
swap(aa[i], aa[j]);
}
for (int h = 0; h < l; h++) {
int m = 1 << h, w = power(3, MD - 1 >> h + 1);
if (inverse)
w = power(w, MD - 2);
long long w_ = 1;
for (int r = 0; r < m; r++) {
for (int i = r, j; i < n; i += m << 1) {
int a = aa[i], b = aa[j = i + m] * w_ % MD;
if ((aa[i] = a + b) >= MD)
aa[i] -= MD;
if ((aa[j] = a - b) < 0)
aa[j] += MD;
}
w_ = w_ * w % MD;
}
}
}
void convolute(int *aa, int *bb, int l) {
int n = 1 << l;
ntt(aa, l, false);
ntt(bb, l, false);
for (int i = 0; i < n; i++)
aa[i] = (long long) aa[i] * bb[i] % MD;
ntt(aa, l, true);
long long v = power(n, MD - 2);
for (int i = 0; i < n; i++)
aa[i] = aa[i] * v % MD;
}
int main() {
int n, m; cin >> n >> m;
int l = 0, n_ = 1;
while (n_ < n + m + 1)
l++, n_ <<= 1;
cin >> cc;
for (int i = 0; i < n; i++)
aa[i] = cc[n - 1 - i] - '0';
cin >> cc;
for (int i = 0; i < m; i++)
bb[i] = cc[m - 1 - i] - '0';
convolute(aa, bb, l);
for (int i = 0; i + 1 < n_; i++)
aa[i + 1] += aa[i] / 10, aa[i] %= 10;
while (n_ > 1 && !aa[n_ - 1])
n_--;
for (int i = 0; i < n_; i++)
cc[i] = aa[n_ - 1 - i] + '0';
cc[n_] = '\0';
cout << cc << '\n';
return 0;
}
