foo.cpp: In function 'int main()':
foo.cpp:33:15: error: expected ')' before numeric constant
 a1[i] = (a1[i]10+a[j]-'0')%p1;
               ^
foo.cpp:34:15: error: expected ')' before numeric constant
 a2[i] = (a2[i]10+a[j]-'0')%p2;
               ^
foo.cpp:35:15: error: expected ')' before numeric constant
 a3[i] = (a3[i]10+a[j]-'0')%p3;
               ^
foo.cpp:36:15: error: expected ')' before numeric constant
 a4[i] = (a4[i]10+a[j]-'0')%p4;
               ^
foo.cpp:17:9: warning: unused variable 'k' [-Wunused-variable]
 int i,j,k;
         ^