diff --git a/chapter-5/5-1.c b/chapter-5/5-1.c
new file mode 100644
index 0000000..c46ca97
--- /dev/null
+++ b/chapter-5/5-1.c
@@ -0,0 +1,37 @@
+
+#include <ctype.h>
+#include <stdio.h>
+#define SIZE 100
+
+int getint(int *pn) {
+  int c, sign;
+  while (isspace(c = getchar())) /* Ignore whitespace*/
+    ;
+  if (c != '+' && c != '-' && !isdigit(c) && c != EOF) {
+    ungetc(c, stdin);
+    return 0;
+  }
+  sign = (c == '-') ? -1 : 1;
+  if (c == '+' || c == '-') {
+    c = getchar();
+    if (!isdigit(c)) {
+      ungetc(c, stdin);
+      return c;
+    }
+  }
+
+  for (*pn = 0; isdigit(c); c = getchar())
+    *pn = 10 * *pn + (c - '0');
+  *pn *= sign;
+
+  if (c != EOF)
+    ungetc(c, stdin);
+  return c;
+}
+
+int main() {
+  int n;
+  double array[SIZE];
+  for (n = 0; n < SIZE && getfloat(&array[n]) != EOF; n++)
+    ;
+}