feat: create structure for the project and first problem

app/routers/__init__.py

@@ -0,0 +1,4 @@
+from app.routers.math import router as api_router
+
+
+__all__ = ["api_router"]

app/routers/grade_1.py

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+from fastapi import APIRouter, HTTPException
+
+from app.problems.grade_1.join_pictures_with_quantity import (
+    join_pictures_with_quantity,
+)
+from app.schemas.grade_1.join_pictures_with_quantity import (
+    JoinPicturesWithQuantityProblem,
+    JoinPicturesWithQuantityRequest,
+)
+
+router = APIRouter(prefix="/grade_1", tags=["Grade 1"])
+
+
+@router.post(
+    "/join_pictures_with_quantity",
+    response_model=JoinPicturesWithQuantityProblem,
+)
+def create_join_pictures_with_quantity_problem(
+    request: JoinPicturesWithQuantityRequest,
+) -> dict:
+    try:
+        return join_pictures_with_quantity(
+            available_pictures=[
+                picture.model_dump() for picture in request.available_pictures
+            ],
+            container_count_per_side=request.container_count_per_side,
+            min_quantity=request.min_quantity,
+            max_quantity=request.max_quantity,
+            seed=request.seed,
+        )
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc

app/routers/math.py

@@ -0,0 +1,7 @@
+from fastapi import APIRouter
+
+from app.routers import grade_1
+
+
+router = APIRouter(prefix="/math")
+router.include_router(grade_1.router)