include<bits/stdc++.h>

using namespace std; int main( ) {

int n, k;

cin >> n >> k; for (int i = 0; i < k; i++) {

if (n % 10 != 0) {
	n -= 1;
}
else if(n % 10 == 0) {
	n /= 10;
}

} cout << n;

return 0;

}