What will come in place of the question mark (?) in the following equation, if ‘+’ and ‘−’ are interchanged and ‘×’ and ‘÷’ are interchanged?

What will come in place of the question mark (?) in the following equation, if ‘+’ and ‘−’ are interchanged and ‘×’ and ‘÷’ are interchanged?
यदि ‘+’ और ‘−’ को परस्पर बदल दिया जाए तथा ‘×’ और ‘÷’ को परस्पर बदल दिया जाए, तो निम्नलिखित समीकरण में प्रश्न-चिह्न (?) के स्थान पर क्या आएगा?
26 × 2 − 21 + 7 ÷ 4 = ?