On this day, 44 years ago, on December 13, 1981 (November 18, 1981 in the lunar calendar), a paper currency dispute broke out in Argentina. In December 1981, the Argentine Ministry of Finance announced that all banknotes with a face value of 1 million pesos issued in 1980 would be cancelled and banknotes newly designed in 1981 would be replaced. In 1980, in order to adapt to the needs of inflation, the Argentine government decided to print notes with a face value of 1 million pesos. The design on the ticket at that time was a hydropower project jointly built by Uruguay and Argentina. Someone discovered that the pattern was on the Uruguayan side of the project, but it was too late and 16 million banknotes had been printed. In order to correct the above mistakes, Argentine banknote designers designed a new pattern, namely the Plaza de Mayo on Independence Day in Buenos Aires. In this way, previously printed banknotes will be declared invalid.