Help solving an exercise

Hi all, suppose I have this C code:

#include<stdlib.h>
int main(int argc, char *argv[]) {
	int a = atoi(argv[1]);
	a = a - 10;
	int b = a + 1;
	if ( b > 3 )
	    malloc(b);
}

Once compiled the call to malloc is at 0x00000000004005a6

With angr I would like to obtain the min value for argv1 if I have the malloc to be called. The solution should be 13 but I cannot have that result. My code is the following:

import angr

def main():
	proj = angr.Project('./example', load_options={"auto_load_libs": False})
	argv1 = angr.claripy.BVS("argv1", 64)
	initial_state = proj.factory.entry_state(args=["./example", argv1]) 

	initial_path = proj.factory.path(initial_state)
	path_group = proj.factory.path_group(initial_state)
	path_group.explore(find=0x00000000004005a6)
	found = path_group.found[0]
	print found.state.se.min(argv1)

if __name__ == '__main__':
    main()

My output is:

3112040326038040883

Can you explain me why please?

Thanks

[axt]

@frapik99 check get_signed_range function here: https://github.com/axt/angr-utils/blob/master/angrutils/expr.py

[ltfish]

You can add a new constraint that limits the most significant bit of your symbolic variable argv1 to 0 (positive numbers) or 1 (negative numbers), and then call se.min() or se.max() respectively.