// set breakpoint in function 

// compile with gdb support
g++ -g -o runme main1.cpp


// start gdb 
gdb runme

// set a breakpoint 
break SumOfTwo

// run program 
run


// it should stop upon entering the function SumOfTwo
// show a backtrace... backtrace or bt
bt

// if you want to switch to a specific frame

frame 1

// print the variables
info locals