c# - Specified cast is not valid, getting all values from jagged array -

specified cast not valid, please tell me way max/min value values stored in array, not specific index.

int max = jarray.cast<int>().max();                  system.console.write("\n\n max marks:" + max ); 

declaration of jagged array:

 string totalstudents;          system.console.write("enter total no. of students:");         totalstudents = console.readline();          int value;         bool result = int.tryparse(totalstudents, out value);          jaggedarray jag = new jaggedarray(value);          int[][] jarray = new int[jag.noofstudents][];            (int = 0; < jag.noofstudents; i++)         {               system.console.write("enter total no. of subjects of student:" + + ":\t");             string totalsubjects = console.readline();              int subjectvalue;             bool sresult = int.tryparse(totalsubjects, out subjectvalue);             jarray[i] = new int[subjectvalue];              (int = 0; < subjectvalue; a++)             {                 system.console.write("\nenter marks obtained of subject:" + + " of student " + + ":\t");                 string totalmarks = console.readline();                  int marksvalue;                 bool mresult = int.tryparse(totalmarks, out marksvalue);                 jarray[i][a] = marksvalue;              } 

jarray jagged array(array of arrays), that's why specific cast int invalid.

i suggest flatten structure using selectmany , max.

int max = jarray.selectmany(x=>x.toarray()).max();