Solved EDIT.

EDIT/source.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+int main() {
+  int capital[1001], non_capital[1001];
+  char s[1001];
+
+  int i, j;
+
+  while(scanf("%s", s) != EOF) {
+    int l = strlen(s);
+
+    for(i = 0; i <= l; ++i) {
+      capital[i] = 0;
+      non_capital[i] = 0;
+    }
+
+    for(j = l - 1; j >= 0; --j) {
+      capital[j] = non_capital[j + 1] + (isupper(s[j])? 0: 1);
+      non_capital[j] = capital[j + 1] + (isupper(s[j])? 1: 0);
+    }
+    printf("%d\n", (capital[0] < non_capital[0])? capital[0]: non_capital[0]);
+  }
+  return 0;
+}

EDIT/source.py

@@ -0,0 +1,23 @@
+#!/usr/bin/python
+
+def min_dist(m):
+    length = len(m)
+    capital = [0] * (length + 1)
+    non_capital = capital[:]
+
+    for i in range(length-1, -1, -1):
+        capital[i] = non_capital[i+1] + (0 if m[i].isupper() else 1)
+        non_capital[i] = capital[i+1] + (1 if m[i].isupper() else 0)
+
+    return min(capital[0], non_capital[0])
+
+def main():
+    while True:
+        try:
+            m = raw_input()
+            print str(min_dist(m))
+        except EOFError:
+            break
+
+if __name__ == "__main__":
+    main()