The most rational way for Greece to cope with its massive sovereign debt problem is to quit the Eurozone, the head of Russia’s largest bank Sberbank, German Gref said on Wednesday on the sidelines of the World Economic Forum in Davos, Switzerland .

“In this case, this would be similar to the (Russian) proverb that says: ‘A terrible end is better than an endless horror,’” Gref said on the opening day of the forum.

Greece’s exit from the eurozone would help the country gradually increase growth and competitiveness by devaluing the national currency. Greece’s withdrawal would also define more clearly development prospects for Greece and the 17 European countries using the euro as their common currency, Gref said.

“Perhaps we need to talk not only about Greece but about other peripheral eurozone countries with uncompetitive economies. I don’t understand how they can raise the competitive edge of their economies with such a huge debt and with such a strong euro,” he said.

The Russian ruble made major advances on Wednesday, gaining against the euro and the dollar as investors worried about the lack of progress in talks between European finance ministers and bondholders to resolve Greece’s debt problem.

The ruble, propped up by high world oil prices, with Brent crude currently hovering at about $110 per barrel, surged by 32 kopeks against the euro, sending the single European currency to a five-month low of 39.8770 in MICEX trading, past the psychologically important 40 ruble level in Wednesday afternoon trading.

Greece is holding talks with the holders of some 206 billion euros ($260 billion) in Greek sovereign debt, trying to get its creditors to swap government bonds for new securities with half the face value or less. The scope of the debt write-off and a new coupon rate have been a stumbling block in the debt negotiations.

International lenders comprising the European Central Bank, the International Monetary Fund and the European Union have insisted that the deal is essential for Greece to receive more aid to repay its massive 360 billion euro debt.

Greece faces an important bond repayment deadline in March and European leaders fear that the country might default on its March 20 bond payment, which could trigger panic on the markets.