foo.cpp: In function 'int main()':
foo.cpp:53:19: error: 'system' was not declared in this scope
     system("pause");
                   ^
foo.cpp:40:9: warning: unused variable 'i' [-Wunused-variable]
     int i,j,la,lb;
         ^
foo.cpp:40:11: warning: unused variable 'j' [-Wunused-variable]
     int i,j,la,lb;
           ^