Python: If input$\_$year is in the inclusive range:

$1960-1969,$ output 'The $60$s$\text{'}.$

$1970-1979,$ output 'The $70$s$\text{'}.$

$1980-1989,$ output 'The $80$s$\text{'}.$

Otherwise, output 'Not in the period of research'.

Ex $1$: If the input is $1966,$ then the output is:

The $60$s

Ex $2$: If the input is $1976,$ then the output is:

The $70$s

Ex $3$: If the input is $1984,$ then the output is:

The $80$s

Ex $4$: If the input is $2005,$ then the output is:

Not in the period of research