diff --git a/numbers/sum.c b/numbers/sum.c
new file mode 100644
index 0000000..c6199ab
--- /dev/null
+++ b/numbers/sum.c
@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include <string.h>
+
+int pow_(int x, int y) {
+	if (!y) {
+		return 1;
+	}
+	int res = x;
+	for (int i = 1; i <= y-1; ++i) {
+		res = res*x;
+	}
+	return res;
+}
+
+int main(int argc, char *argv[]) {
+	char z[10000];
+	if (argc)
+		strcpy(z, argv[1]);
+	
+	float x; 
+	int y;
+	scanf("%f %x", &x, &y);
+	
+	int len = strlen(z);
+	int res = 0;
+	for (int i = len-1; i >= 0; --i) {
+		if (z[i]>=48 && z[i]<=57) {
+			res += (z[i] - '0') * pow_(27, len-i-1);	
+		}
+		else {
+			res += (z[i] - 54) * pow_(27, len-i-1);
+		}
+	}
+	printf("%.3f\n", x+y+res);
+}
+
+