Excel reading and writing certain conditions required please help

I am reading columns from multiple excel. I need to make some conditions and formulas while writing new excel. I couldn’t do it, errors came up.

Read Excel.xlsx (11.8 KB)
Write Excel.xlsx (8.6 KB)

Main.xaml (25.9 KB)

I need to read the values ​​and add formulas to some of them and patch them. then i need to print to new excel

Used write cell activity and in
used Assign value to write the formula then used write cell activity

I get mistakes when I do that.

SDT1 & SDT2 double to string ? or int32 ?

used variable(T3) as type double