#include <stdio.h>#include <string.h>#define MAX 11000void reverse(char *from, char *to);void call_mult(char *first, char *second, char *result);void call_minus(char *first, char *second, char *result);void call_add(char *first, char *second, char *result);void call_divide(char *first, int div, char *result);int main(){char buf[MAX], temp[MAX];int n, k, i;char res[MAX];setvbuf(stdout, NULL, _IONBF, 0);while (scanf("%d%d", &n, &k) != EOF) {sprintf(buf, "%d", n);for (i = 1; i < k; i++) {sprintf(temp, "%d", n - i);call_mult(buf, temp, res);strcpy(buf, res);}for (i = 2; i <= k; i++) {call_divide(buf, i, res);strcpy(buf, res);}printf("%d\n", strlen(res));}return 0;}void reverse(char *from, char *to){int len = strlen(from), i;for (i = 0; i < len; i++) {to[i] = from[len - 1 - i];}to[len] = '\0';}void call_mult(char *first, char *second, char *result){char F[MAX], S[MAX], Res[MAX];int f_len, s_len, f, s, r, r_len, sum, carry;f_len = strlen(first);s_len = strlen(second);r_len = f_len + s_len;r = -1;reverse(first, F);reverse(second, S);for (f = 0; f < r_len; f++)Res[f] = '0';Res[f] = '\0';for (s = 0; s < s_len; s++) {for (f = 0, carry = 0; f < f_len; f++) {sum = (F[f] - '0') * (S[s] - '0') + (Res[f + s] - '0') + carry;Res[f + s] = sum % 10 + '0';carry = sum / 10;if (f + s > r)r = f + s;}while (carry) {sum = (Res[f + s] - '0') + carry;Res[f + s] = sum % 10 + '0';carry = sum / 10;if (f + s > r)r = f + s;f++;}}for (; r > 0 && Res[r] == '0'; r--);Res[r + 1] = '\0';reverse(Res, result);}void call_minus(char *first, char *second, char *result){char F[MAX], S[MAX];int f_len, s_len, now, borrow, sum;f_len = strlen(first);s_len = strlen(second);reverse(first, F);reverse(second, S);for (now = 0, borrow = 0; now < f_len && now < s_len; now++) {sum = (F[now] - '0') - (S[now] - '0') - borrow;if (sum < 0) {borrow = 1;F[now] = sum + 10 + '0';} else {borrow = 0;F[now] = sum + '0';}}for (; now < f_len && borrow; now++) {sum = (F[now] - '0') - borrow;if (sum < 0) {borrow = 1;F[now] = sum + 10 + '0';} else {borrow = 0;F[now] = sum + '0';}}for (now = f_len - 1; now > 0 && F[now] == '0'; now--);F[now + 1] = '\0';reverse(F, result);}void call_add(char *first, char *second, char *result){char F[MAX], S[MAX], Res[MAX];int f_len, s_len, now, carry, sum;f_len = strlen(first);s_len = strlen(second);reverse(first, F);reverse(second, S);for (now = 0, carry = 0; now < f_len && now < s_len; now++) {sum = (F[now] - '0') + (S[now] - '0') + carry;Res[now] = sum % 10 + '0';carry = sum / 10;}for (; now < f_len; now++) {sum = (F[now] - '0') + carry;Res[now] = sum % 10 + '0';carry = sum / 10;}for (; now < s_len; now++) {sum = (S[now] - '0') + carry;Res[now] = sum % 10 + '0';carry = sum / 10;}if (carry)Res[now++] = carry + '0';Res[now] = '\0';reverse(Res, result);}void call_divide(char *first, int div, char *result){char Res[MAX];int len = strlen(first);int remainder = 0, now, sum;for (now = 0; now < len; now++) {sum = remainder * 10 + (first[now] - '0');Res[now] = sum / div + '0';remainder = sum % div;}Res[now] = '\0';for (now = 0; Res[now] == '0'; now++);strcpy(result, &Res[now]);if (strlen(result) == 0)strcpy(result, "0");}