View Compilation Error

0_0_32919510_20967.cpp: In function 'int main()':
0_0_32919510_20967.cpp:56:13: error: 'cin' was not declared in this scope
             cin>>a>>b>>q>>p;
             ^
0_0_32919510_20967.cpp:66:9: error: 'cin' was not declared in this scope
         cin>>s>>t;
         ^