diff --git a/components/SlidesGenerator.tsx b/components/SlidesGenerator.tsx
index 8c82609..a1f1da4 100644
--- a/components/SlidesGenerator.tsx
+++ b/components/SlidesGenerator.tsx
@@ -1140,6 +1140,7 @@ export default function SlidesGenerator() {
                                         onChange={(e) => setSlideCount(parseInt(e.target.value))}
                                         className="w-full rounded-md border border-input bg-background px-2.5 py-1.5 text-xs ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
                                     >
+                                        <option value={0}>{t.sameAsSource}</option>
                                         {[5, 8, 10, 12, 15, 20, 25, 30].map((n) => (
                                             <option key={n} value={n}>{n} slides</option>
                                         ))}
diff --git a/lib/i18n/translations.ts b/lib/i18n/translations.ts
index 3e2acbf..e7496d3 100644
--- a/lib/i18n/translations.ts
+++ b/lib/i18n/translations.ts
@@ -121,6 +121,7 @@ export const translations = {
             audience: "Target Audience",
             animations: "Animation Style",
             numSlides: "Number of Slides",
+            sameAsSource: "Same as source",
             generate: "Generate Presentation",
             generating: "Crafting your story...",
             emptyState: "Your presentation will appear here",
@@ -281,6 +282,7 @@ export const translations = {
             audience: "Целевая аудитория",
             animations: "Стиль анимации",
             numSlides: "Количество слайдов",
+            sameAsSource: "Как в источнике",
             generate: "Создать презентацию",
             generating: "Создаем вашу историю...",
             emptyState: "Ваша презентация появится здесь",
@@ -441,6 +443,7 @@ export const translations = {
             audience: "קהל יעד",
             animations: "סגנון אנימציה",
             numSlides: "מספר שקופיות",
+            sameAsSource: "כמו במקור",
             generate: "חולל מצגת",
             generating: "יוצר את הסיפור שלך...",
             emptyState: "המצגת שלך תופיע כאן",
diff --git a/lib/services/ollama-cloud.ts b/lib/services/ollama-cloud.ts
index a18f079..a5e927f 100644
--- a/lib/services/ollama-cloud.ts
+++ b/lib/services/ollama-cloud.ts
@@ -405,7 +405,7 @@ AUDIENCE STYLE: ${audienceStyle}
 ${organization ? `ORGANIZATION BRANDING: ${organization}` : ""}
 
 REQUIREMENTS:
-- Create EXACTLY ${slideCount} slides
+- ${slideCount > 0 ? `Create EXACTLY ${slideCount} slides` : "Maintain the exact number of slides/pages from the provided source presentation/document context. If no source file is provided, generate 10 slides by default."}
 - ALL content in ${language}
 - Each slide MUST have complete htmlContent with inline <style> tags
 - Use animation-delay for staggered reveal effects
diff --git a/lib/services/qwen-oauth.ts b/lib/services/qwen-oauth.ts
index a2aaf0d..2522f4a 100644
--- a/lib/services/qwen-oauth.ts
+++ b/lib/services/qwen-oauth.ts
@@ -732,7 +732,7 @@ AUDIENCE STYLE: ${audienceStyle}
 ${organization ? `ORGANIZATION BRANDING: ${organization}` : ""}
 
 REQUIREMENTS:
-- Create EXACTLY ${slideCount} slides
+- ${slideCount > 0 ? `Create EXACTLY ${slideCount} slides` : "Maintain the exact number of slides/pages from the provided source presentation/document context. If no source file is provided, generate 10 slides by default."}
 - ALL content in ${language}
 - Each slide MUST have complete htmlContent with inline <style> tags
 - Use animation-delay for staggered reveal effects
diff --git a/lib/services/zai-plan.ts b/lib/services/zai-plan.ts
index 2c07335..309ca8b 100644
--- a/lib/services/zai-plan.ts
+++ b/lib/services/zai-plan.ts
@@ -370,7 +370,7 @@ AUDIENCE STYLE: ${audienceStyle}
 ${organization ? `ORGANIZATION BRANDING: ${organization}` : ""}
 
 REQUIREMENTS:
-- Create EXACTLY ${slideCount} slides
+- ${slideCount > 0 ? `Create EXACTLY ${slideCount} slides` : "Maintain the exact number of slides/pages from the provided source presentation/document context. If no source file is provided, generate 10 slides by default."}
 - ALL content in ${language}
 - Each slide MUST have complete htmlContent with inline <style> tags
 - Use animation-delay for staggered reveal effects