#include <stdio.h>
#include <stdlib.h>
 
int factorial(int n, int acc) {
  if (n == 0) {
    return acc;
  } else {
    return factorial(n - 1, acc * n);
  }
}
 
int foo(int n, int acc) {
  if (n == 0) {
    return acc;
  } else {
    return foo(n - 1, factorial(n, 1) + acc);
  }
}
 
int main(void) {
  char s[3];
  puts("1以上10以下の整数を入力してください");
  scanf("%2s%*[^\n]", s);
  int n = strtol(s, NULL, 10);
  if (n < 1 || n > 10) {
    return EXIT_FAILURE;
  } else {
    printf("%d\n", foo(n, 0));
  }
  return EXIT_SUCCESS;
}
 

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