diff --git a/atoi b/atoi
new file mode 100755
index 0000000..bab7f89
Binary files /dev/null and b/atoi differ
diff --git a/atoi.c b/atoi.c
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--- /dev/null
+++ b/atoi.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <string.h>
+int myatoi(char *s, int l);
+int main(int argc, char **argv)
+{
+	printf("Print your string number\n");
+	char s[100]; scanf("%s", s);
+	printf("Your converted number is %d\n",  myatoi(s, strlen(s)));
+	return 0;
+}
+int myatoi(char *s, int l) 
+{	
+	int result = 0;
+	int is_pos = 1;
+	for(int i=0; i < l; i++)
+	{
+		if((int)s[i]==45)
+			{
+				is_pos = -1;
+			}
+		else
+			{
+				if((int)s[i] < 48 || (int)s[i] > 57)
+				{
+					printf("Not a number\n");
+					result = 0;
+					break;
+				}
+					result = result * 10 + ((int)s[i] - 48);
+			}
+	}
+	result = result * is_pos;
+	return result;
+}